The Half-Life: Opposing Force Ultimate Strategy Guide (PC version)
This FAQ is copyright 2008-2010 by Stanley E. Dunigan (firstname.lastname@example.org).
This FAQ may be posted and used anywhere by anyone as long as it's unaltered, but always check one of the official host websites listed below for the latest version.
GameFAQs (www.gamefaqs.com) -- always the first site updated
GameBoomers (www.gameboomers.com) -- official source of this RTF version
Cheat Happens (www.cheathappens.com)
Check the Universal Hint System for a complete Half-Life: Opposing Force hint file. It's not a FAQ-style walkthru, but instead organizes the hints into a hypertext-like Q&A document, making it easier to find the hints you need without accidentally seeing other hints you don't want yet.
This FAQ is a *very* complete walkthru of Half-Life: Opposing Force that includes all of the best tips, strategies, and secrets that I've discovered or heard about during my eight years of playing the game. (I bought it at Wal-Mart for over $40 awhile after it came out. I was hoping for a great sale on it like the one on Half-Life when I got it, but I eventually gave up on that.) This walkthru was written as a "companion" to my Half-Life 10th Anniversary Ultimate Strategy Guide, which should be available in the same place you got this from.
To write this walkthru, I played through the game in its original version (18.104.22.168) and with the version 22.214.171.124 patch installed. I also played the stand-alone 126.96.36.199 version that came with Blue Shift. I don't know what all differences other patches make (though I do know that the 188.8.131.52 patch is screwy, since it totally trashed my game), but this walkthru should work pretty well with all versions of the game. Some strategies that key off of exact details or specific creature behavior might need a bit of adjusting, and related updates will be made if I ever get a chance to play other game versions.
If you have a favorite Opposing Force strategy or secret that isn't in this walkthru yet, send me an email at the address listed above in the copyright section. If I like it enough to include it after I try it out, I'll add it to the walkthru and give you credit for it as long as you specifically tell me what contributor name you want me to use.
VERSION 1.26 (1/11/2010) NOTES AND CREDITS
This version mainly updates the email address in the copyright section (the wmconnect.com address is no longer active), though it also includes a few minor formatting improvements and other corrections.
VERSION 1.25 (4/7/2009) NOTES AND CREDITS
I played through the 184.108.40.206 game version again, and carefully reproofed the entire file, fixing errors and making minor improvements. No one's written in with anything, and I probably won't ever be able to find any more new tips, so this is likely to be the last release of this walkthru.
VERSION 1.2 (10/11/2008) NOTES AND CREDITS
I played the stand-alone 220.127.116.11 game version (and replayed the 18.104.22.168 version) and came up with various minor improvements, including:
· easier way to get past steam leaks between fan rooms in section of2a1
· note about sneak-shooting pit drones in the head in section of2a2
· tip for going back for ammo in the alternative method in section of3a1
· another way to barnacle past the pit worm uninjured in section of4a4
· warning about shockroach glitch in game version 22.214.171.124 in section of5a2
· tip about using the mounted laser to score critical hits in section of6a5
· a few little misc. changes
VERSION 1.1 (9/30/2008) NOTES AND CREDITS
For this version, I replayed the game with the 126.96.36.199 patch version installed. I didn't find anything new (except that tripmines can't be used as stepping stones anymore), but I re-proofed the entire walkthru and made quite a few minor adjustments and clarifications. I also added brief descriptive names to each chapter section's title to help you more quickly figure out which one you're in, and I added several sites to the official host website list in the copyright section.
VERSION 1.0 (9/24/2008) NOTES AND CREDITS
This is the original version of this walkthru, so I have no one else to credit yet.
STARTING TIPS AND NOTES
This walkthru is organized around the same major chapter divisions that the game is, with these starting tips and notes put in at the beginning. If you're "joining us with a game already in progress," so to speak, you'll need to search for the title of the chapter that you're in.
Each chapter's info is divided up into sections that correspond to the chunks that the game itself is divided into. Whenever you move from one section to another, you'll see the word "LOADING..." in the middle of the screen while the section you're moving into loads up. Each section has an internal codename, and I use that in naming the sections in this walkthru so that if you're on the PC, you can use the console's "status" command to see what section you're in (check the "map" field). Each section name also has some brief descriptive text in case you'd rather figure out what section you're in that way.
In many places in this walkthru, I refer to the quicksave and quickrestore keys. If you're not already intimately familiar with them, get that way at once! To find out (and/or change) what keys are defined for those functions, go to the game's main menu and choose "Configuration" and then "Controls." I strongly advise you to redefine quicksave to be F5 and quickrestore to be F9. That way, the two keys won't be too close together. (That's practically an industry standard by now, anyway.)
Another thing you should do on the main menu's configuration screen is choose "Video" and then "Video Options," and move the gamma slider all the way to the right. That'll make all the game areas much easier to see in, and it won't blind you or wash out all the colors like some games' full-gamma settings do.
I don't include anything about Boot Camp in these hints, but you should start out by playing through it at least once, especially if you're not yet familiar with how to use ropes to swing across pits and such, and how to use the new sniper rifle to shoot distant targets. Also, replay the main game's Hazard Course if you need a refresher on jump-crouching, which is just as essential in this game as it was in that one.
I mention crouch-walking a lot in this walkthru, but what I'm usually referring to is crouch-running, meaning you're moving around while using the "Duck" key, but not the "Walk" key. True crouch-walking involves using the "Duck" and "Walk" keys at the same time, and makes you move extremely slowly. This is sometimes useful, but usually not necessary. You can take any reference to crouch-walking to really mean crouch-running unless I say to very slowly or very carefully crouch-walk, in which case true crouch-walking should probably be used.
A favorite tactic of mine that I'll often say to use is sneak-shooting. That's when you sneak up on an enemy who's unaware of your presence and position yourself so that you can see only a small part of him, such as an arm or a leg. When you shoot that part, the enemy will often just turn in place to face you. If he still can't see you due to an obstruction to his view, you can keep sneak-shooting exposed parts until he's dead. Some enemies will move around a bit when sneak-shot, but they still won't be aware of you unless they get a clear look at you while moving around. If you're afraid that will happen, quickly strafe to where you'll be out of sight right after taking a sneaky shot.
One fun thing you could do to extend gameplay is to use the wrench or knife to beat on all the dead bodies you find (and make) until they splattify. I've always enjoyed doing that immensely, and I'll never forgive Half-Life 2 for making dead bodies invincible.
Another way to extend gameplay is to play on the highest difficulty setting without using any cheats at all. Once you're good at that, try adding the "damage-free" restriction. It is possible to play all the way through Opposing Force without ever taking even one point of damage from anything. It's often a pain, and there are certain areas where you'll have to retry something several times before you can make it through damage-free, but it can be done (especially if you use all the best strategies in this walkthru).
Section of0a0: FLYING IN
This is mainly the starting osprey ride, where all you can do is look around. After the crash, you can run around briefly at the crash site, but there's no benefit to doing so, especially since you'll be returning there soon. You should just wait and watch until the Welcome to Black Mesa chapter starts.
WELCOME TO BLACK MESA
Section of1a1: EXPLORING THE STARTING BUILDING
After walking up to the scientist and listening to what he has to say, go through the door that's behind him and explore the small wrecky corridor until you find some doors you can push through. Past them, turn left and go straight to reach an area where two scientists are being "fascinated" by how headcrabs take over their victims' nervous systems.
Get the powered combat vest (PCV) from the table near the back of the room, since it's going to be your equivalent of Gordon Freeman's HEV suit. Go back to the overturned table in the corridor and turn left. Keep going until you reach the large windows of a room where a zombie gets up off a slab and throws a clean-suit-clad scientist through one of the windows.
After watching that amusing spectacle, run on down the corridor to where you can go through some wrecked sliding doors with an overturned table next to them. Go down a short hallway and some stairs to reach a large room where one of the new fatguards is shooting down a zombie. Talk to the fatguard to get him to follow you, then go stand next to the retinal-scan doors until he opens them for you.
After quicksaving in case you mess up, go up to the chair that's next to the room's large central table. Push it over to where it's right in between the two retinal-scan doors. Squeeze past the chair without knocking it out of position and go around the corner to pick up the big red wrench (being careful not to touch the dangling live wire), then return to the doors. They'll have tried to close, but the chair should've stopped them from fully closing. If not, quickrestore and try again. (Note that in version 188.8.131.52, the doors may not even try to close if the chair is between them, making it really easy for you.)
When you get the doors properly chair-blocked, quicksave again. Try crouch-jumping onto the top of the chair and then crouch-walking through the door gap that's above the chair. You may have to strafe left or right a bit, and maybe jump again in order to get through. If you make it through without accidentally pushing the chair out from between the doors, quicksave again.
The fatguard will have moved over to a dark spot to the left of the stairs. Go over there and kill him with a wrench power attack. That's done by using the altfire button. You can hold the wrench up by keeping the altfire button pressed down to get a bit more power and to allow you to move into position right before releasing.
Pick up the fatguard's Desert Eagle .357 pistol (which I'll just call the .357 from now on). That's all you can get here, though you can go back to where the zombie threw a scientist through a window and lead it down to the headcrab-studying scientists and/or the infirmary scientist for a bit of fun.
When you're ready to go, return to the chair-blocked doors and quicksave yet again. It's kind of tricky, but you'll have to jump-crouch onto the chair and then crouch-hop your way through the door gap without pushing the chair out of its door-blocking position. Once you make it, quicksave once more, then crouch-walk down the hall, carefully avoiding the dangling live wire.
As you enter the room with the green and purple lasers, crouch-walk under the right end of the green laser. If you try to go past while farther to the left, you may get a fatal haircut. As soon as you're past the green laser, turn left and go over to the staircase. Crouch-walk past the left side of the staircase to get past the purple laser, then turn left and go over to where the purple laser is being reflected off a large, round mirror-like thing.
Go up to the mirror and bash it with the wrench, then wait for the lasers to short out before you go up the stairs. Crouch-walk slowly down the corridor past the stairs until you see two headcrabs drop onto the floor ahead of you. Crouch-walk up to each crab and whack it to death with regular wrench attacks before it can turn and leap at you. Get out the .357 and right-click to turn its laser sight on. Move along the left side of the corridor until you get near the small green toxic waste spill.
Look in the alcove to the right of the spill to see a headcrab. Sneak-shoot it with the .357 for a one-shot kill, then carefully crouch-walk over to it. Look across the toxic spill to see the other nearby headcrab between two sets of computer banks along the left wall. Sneak-shoot it, then jump over the toxic spill at its narrowest point.
Past it, look through an unopenable door to see the ever-annoying G-Man (a.k.a. "Briefcase Bastard") talk to a security guard and walk off. Break open the crates near the stairs to get a health pack and an armor battery, then go up the stairs and through a door to find more crates you can break (and to get to section of1a2).
Section of1a2: FINDING AND GETTING PAST YOUR CRASHED OSPREY
After you bash all the crates and find another health pack, go through the door that leads outside. Turn right and go over to the big path break. You can't quite make the jump to the path piece with the health pack on it, so jump onto the dirt ledge that's directly under it. Go along the ledge, jumping gaps in it, until you get up next to a piece of railed walkway.
You can't jump over the railing, so turn and jump across to the dirt ledge on the other side. At the back of it, you can jump onto a slightly raised dirt ledge, and then get onto the walkway. Walk over the dead vortigaunt to pick up the knife that's stuck in it, then jump across to the walkway piece with the health pack on it if you want to. From near the vort bod, jump across the gap that leads to the doorway of a dark room.
Turn on your night vision so you can stand in the doorway and use the .357 to shoot the headcrab that's on the other side of the room. Keeping night vision on, look around near the headcrab to find a rocky tunnel that you can crouch-walk through. At its other end, slide down some slanty pipes to reach the outdoor area with your crashed osprey in it.
It's currently highly electrified, so turn right and go through the partly open doors under the large concrete arch. Get out the .357 and look for a headcrab near a wall hole ahead. Shoot it, then stay back and shoot any other headcrabs that appear. Two more should drop down, but the last one might not. If it doesn't, you'll have to keep an eye out for it, since it may show up later.
Jump-crouch into the wall hole through its lowest point (this can be kind of hard, so keep trying) to find a hidden armor battery. Jump back out of the hole, then go out the large partly open doors at the other end of the tunnel. Bash all the wooden crates you find outside while a fatguard stupidly gets himself killed on the door of the nearby electrified area.
Crouch-walk through the small vent opening that's just to the right of the electrified area, then follow the shaft along with night vision on until you emerge in a room with a central fan gadget that's shooting out blue electrical bolts. The bolt on the left is continuous, but the two on the right aren't. Wait until the nearest one stops, then run past it and wait for the other one to stop so you can run past it.
Crouch-walk through the next dark vent shaft until you reach a bashable grating. As soon as you exit the shaft, quicksave. You need to run through the gap between the two machines to the right, then turn right to find the generator control box. You might get zap-killed during that run, so quickrestore and try again if you do. Use the switch on the generator control box to shut off the electricity, then go get the .357 that the dumb fatguard dropped.
Push against the door he killed himself on to get it open, then go back through the large partly open tunnel doors and quicksave. Two vorts will teleport in as you move down the tunnel, but both can be avoided if you're fast. Run straight down the tunnel and turn right past the rubble to evade the first vort, then run out through the other partly open doors to exit the tunnel. To make sure the second vort doesn't see you through the door opening, run straight for the osprey and go past it on its left side.
Get the health packs and armor battery near the osprey, then go forward to where a military radio is setting on a small stand next to some crates. Use the radio and bash the crates for ammo, then go bash the other crates that are off to the side if you want to find another health pack. To move on, climb down the ladder that's to the left of the radio, between two blinky black-and-yellow warning markers.
At the bottom of that ladder, turn on your night vision so you can find another ladder nearby to climb down. Past it is another short ladder to climb down (or just drop down), followed by a metal walkway with three barnacles hanging over it. Instead of trying to navigate past the barnacles, jump over the railing just to the left of the walkway's start and drop into the water below, careful not to hit anything solid on the way down.
Explore around until you find a rocky tunnel that leaves the water and takes you to an outdoor area. Look around it to find a dead marine and some .357 ammo on a large chunk of rubble. Get the ammo and return to the water, then look around for a long ladder on a rocky wall near a corner. Climb up it and go down the hallway until you reach a door. Go through that door and along the outside walkway to reach another door. Past it, go down the corridor until section of1a3 loads.
Section of1a3: VORT WALKWAYS AND SELF-DESTRUCTING ROOM
Peek around the corner and let the vort in the room ahead see you, then quickly dodge back out of sight and get out the wrench. Press and hold the altfire key to get the wrench ready for a power attack, then run up to the vort and whack it as soon as it appears ahead of you.
Crouch-walk over to the dead marine that the vort was standing near and pick up the dropped shotgun. Switch to the .357 and make sure it's reloaded, then quicksave. Crouch-walk over to the start of the metal walkway. If you look down and to the right of the walkway, you should be able to see and shoot a vort that's on a lower walkway. A head shot will mean an instant kill, so try for that.
Climb down the ladder at the other end of the walkway on your level, then crouch-walk slowly forward and a bit to the left to get to where you can see and shoot the vort on the walkway that's below this one. After it's dead, crouch-walk along the walkway with night vision on. There are some steam hazards that need to be crouch-walked under and a barnacle tongue that needs to be avoided.
After you climb down to the lowest walkway, move along it to reach a door, being careful to avoid the barnacle tongue that's hanging over the walkway near the door. Get out the wrench, then go through the door and up the steps. Turn right and run over to a railing, then jump it to land on the floor below. Quickly bash both wooden crates to get a health pack and armor battery, then run through the doorway that's over to the left. If you're fast enough, you'll avoid the notice of the two vorts that are riding down on a nearby cargo lift.
When you reach the cracked walkway segment that leads to the next room's floor, jump to the segment and quickly run onto the floor before the segment breaks off. Look to the left to see a broken-off yellow ladder on one wall. You can't reach it, so start moving slowly toward the door on the room's other side. When an explosion causes the room to start falling apart, run back to the spot under the broken-off yellow ladder and stand there.
Wait until the nearest upper walkway segment falls down to where you can jump onto it. Do so, then run up it and turn left. To make sure you don't fall off, crouch-walk your way over to the door that you can see ahead. Push up against the door until it opens (thanks to the G-Man, who's actually helpful for once), then run through it and down the hallway until you reach a small lift. Use the button on the wall to lower the lift and enter section of1a4.
Section of1a4: ELECTRIFIED SLUDGE ROOM
When you enter the big room with the electrified toxic spill, look to the left to find some .357 ammo on a green crate. Jump-crouch onto the crate to get the ammo, then bash the nearby wooden crate to find a health pack. Shoot the explosive crate on the hanging conveyor platform with the shotgun to blow it up, then quicksave and jump across the green sludge.
If you don't make it uninjured, quickrestore and try again. You might want to try jumping from on the green crate you got the ammo from. Or if you don't need health, don't bash the big wooden crate. Jump-crouch onto it from on the green crate, then jump to the conveyor and drop down onto the floor past the toxic spill.
After you make it across, go up to the nearest wooden crate. Get out the knife and break the crate, then quickly strafe left to avoid the headcrab that was hiding in the area behind the crate. It should leap far enough to touch the electrified toxic water and die, but be ready to quickly charge it and hack it with the knife if it doesn't.
Get the shotgun shell box from the floor, then get out the .357. Move along while looking across the green water until you see a headcrab on a green crate. Shoot it, then turn to the left and move to where you can see another headcrab on a green crate. It can be kind of hard to see because there's a taller green crate right behind the one it's on.
After you shoot that headcrab, get out the shotgun and blow up the explosive crate that's just past the green crates to kill another crab. Use the .357 to sneak-shoot the crab that's hiding between wooden crates to the right, then go over to the stairs and quickly shoot down the two crabs that are partway up them.
Break open the wooden crates to find more shotgun ammo, then go up the stairs to find a room with a first aid station and the cargo conveyor's control panel. The button on the panel is useless, so use the lever to move the conveyor left. Press and hold the "Use item" key until the conveyor is as far left as it'll go, then release the "Use item" key and press it again briefly to move the conveyor back to the right just a little.
Jump onto the control panel, then crouch down and hop through the window. Drop onto the green grate stack that's nearest the conveyor, then jump to the conveyor. From there, jump to the green crate with an armor battery on top of it. Drop carefully down to the floor in the corner, then use the button to the left of the large closed door to open it.
Jump-crouch onto the smaller green crate, then onto the bigger one again. Jump back to the conveyor, then quicksave before trying to jump over to the green crate to the right of the newly opened door (the one you shot a headcrab on earlier). It can be a tough jump to make, and you may have to return to the control room and reposition the conveyor a little before you can do it.
Or you could move the conveyor to the right until it's near the large green crates that are next to the one you're trying to get to. Crouch-hop out the control room's window again, then jump to the conveyor from the green crate stack nearest it. It'll then be easy to jump across to the large green crates and crouch-drop onto the headcrab's crate.
Quicksave again once you make it to the headcrab's crate, then make the jump to the floor past the door. It's another hard one to make, so keep quickrestoring and trying again until you make it uninjured. Go down the wide corridor to reach a big room with two lowered crossing barriers.
Either crouch-walk your way under both barriers, or use the button on the first barrier to raise them. In the wrecky area at the end of the walkway, look for a large broken-open pipe in a big wall hole. Jump through the pipe's hole to drop down to section of1a4b.
Section of1a4b: CRATE-CARRYING ROBOT ROOM AND TRAM CAR
After you fall into a large pool of water, look around at water level for a broken grating that you can swim through. In the next flooded room, you can either avoid barnacle tongues while searching for a ladder, or you can let them catch you, then hack them with the knife when they pull you in close.
You'll find the ladder you're after on the wall in the corner that's a ways to the right of the broken grating you swam in through. Climb up the ladder to a metal walkway, then go along the walkway to reach a corridor with three barnacles in it. If you run through fast enough, you might be able to make it before the barnacles' tongues fully lower. Otherwise, let each one catch you so you can slash it.
Turn right after crossing a short bridge to find a green crate you can jump onto to get some .357 ammo and hand grenades. Continue down the hallway to reach a door that leads to a room with flashing red lights. Turn left to see a crate-carrying robot on the floor below that's jammed because some crates are in its way.
Use the shotgun to blow up one of the explosive crates, then go down to the other end of the walkway and wait until the bars that are blocking the nearby ladder retract. Climb down the ladder, turn to face the nearest crates, then quicksave. Jump to the crates, then quickrestore and try again if you overshoot and end up in the toxic goo.
From the second of the nearest crates, jump to the larger one that's ahead, then jump to the ones that are next to the safe walkway. Go up to the sewage overflow control panel and use its big yellow button, then wait as most of the toxic waste is pumped out of the room. Avoid the remaining waste pools as you go over to the large doors at the other end of the room. Use the button to the right of the doors to open them, then get on the lift that's past them.
Get out the .357, then use the button on the wall to get the lift to take you up to another area. Quickly shoot down the four houndeyes in that area before they can zap you with their sonic charges. Go up the huge ramp and over to where you can see a tram car on a nearby track. After quicksaving, take a running jump at the tram's open door, crouching as you approach it. After you make it, move to the back of the tram to get it going, which starts the "We Are Pulling Out" chapter.
"WE ARE PULLING OUT"
Section of1a5: TRAM RIDE
When the tram starts moving upward, go to its front left corner and stay crouched there until it stops moving upward. That should protect you from the nearby vorts without you having to use ammo on any of them. After that, just wait until the tram stops and section of1a5b loads.
Section of1a5b: FATGUARD FOLLOWER AND VORT ROOM
Get out the shotgun and leave the tram car. Move slowly onto the concrete walkway while facing the tram and looking to the left of its door. When a vort teleports in, run up to it and double-barrel it to kill it, then immediately run up next to the tram and crouch down. Wait while crouched until the vort that appears on top of the tram stops moving, then get out the .357 and deliver a carefully aimed head shot to kill it.
Get the 9mm pistol and bullet clips from the nearby corner, then follow the walkway to a room where a hungry fatguard is trying to steal a snack from a vandalized vending machine. You can vandalize the soda machine for him, but he won't appreciate it. Get the wrench out and hold down the "Secondary attack" key, then go through the room's smaller doorway and power-attack the zombie that's standing just to the left of it. If that doesn't kill it, run back through the doorway and let the fatguard finish it off for you.
Get the fatguard to follow you, then go through the zombie's doorway and up some stairs. Quicksave before entering the room beyond, then move into it far enough for a headcrab to drop down ahead of you. Quickly retreat and see if your fatguard can kill both headcrabs and zombies by himself. If he gets killed, quickrestore and try again, this time helping him out a little with your .357.
Let him shoot the two houndeyes you meet as you go up the stairs, plus the vort that teleports in past the last set of stairs. Go up to the large window past the vort and wait for it to be shattered by a shocktrooper teleporting out. Crouch-jump through the window, then grab the pistol that the shocktrooper-shot guard dropped. Push up against the other side of the locked door that's near the large window to open it for your fatguard companion.
Go down the hall until you reach a security door, then stop near it to get the fatguard to open it for you. The room beyond has two AR grenades and an AR bullet clip, so be sure to pick all of that up. You can bash the glass out of the window across the hall and crouch-jump into the room beyond, but all that's in there is a scientist who can heal you if your health is low (which it shouldn't be).
Go to the end of the corridor where it leads into a room with a big lift, then turn to face the fatguard. Back up slowly while looking up until a headcrab jumps out through a broken vent above you. Quickly strafe right so the fatguard won't hit you while shooting at the crab. After quicksaving, back up onto the lift and jump up and down to get the other crab to leap out at you.
Doing so will also get the marine and the three vorts in the room at the top of the lift to start fighting. After dodging the crab, you'll want to look up there and see if you can shoot a vort. You might or might not be able to. If not, you may want to quickrestore and try again. After you get that vort (or give up on it), kill the fatguard with a powered-up wrench whack to get his gun.
Get out the .357 or shotgun and quicksave again, then use the big lift's button to ride it up to the vort-infested room above. If you managed to kill one from below, there will only be two left, but they'll both start charging up to zap you as soon as you rise into their view.
If you quickly shoot them with the .357 or shotgun, not taking the time to line up careful head shots, you should be able to kill them both without getting zapped. Try shooting them alternately, rather than shooting one until it's dead and only then moving on to the other one. If you get zapped, quickrestore and try again, remembering exactly where each vort is to help you shoot them more quickly.
If there are still three vorts up there, try riding the lift up while crouched behind one of its two side railings so that one of the vorts won't be able to zap you without moving. You might then be able to kill the other two without getting zapped, then quickly kill the third one. Another thing you could try is riding the lift up without first jumping up to get the marine to start fighting the vorts. They may be a bit slower to attack you if they've just killed the marine when you come into their view.
Walk around near the dead marine to pick up his Mp5 assault rifle (AR for short), then immediately reload it. Bash all the wooden boxes in the room to find ammo, then use the HEV wall station until it's drained. Jump-crouch onto the green crate to the right of the HEV station, then move up next to the station and jump on top of it. Bash out the grating above the station, then crouch-jump into the vent shaft. Move along it until section of1a6 loads.
Section of1a6: GETTING LEFT BEHIND
In the vertical shaft you come to, climb the ladder to the top, then get onto the small metal platform. Crouch-walk over to the vent shaft opening, then go through it to quickly reach a grating. Bash it, then drop down into a large room. Use the first aid station on one wall if you need to, then go through the door.
In the next room, the marine at the radio will be issuing the message to Cooper that you (as Gordon Freeman) heard near the end of the Surface Tension chapter in the main game. Love those cool tie-ins! After the marine stands up and talks to you, kill him with a single powered-up wrench whack to the head.
Get his dropped gun, plus the hand grenades and C4 satchel bomb that are on the table on the opposite side of the room, then go through the door near the radio. Get the bullets and .357 ammo from the table to the right of the big window, then go over to where a marine is menacing a captured scientist. Kill the marine with a powered-up wrench whack after he takes up a position in the doorway, then grab his gun and enter the room.
Jump-crouch up to the top green crate, then go along the adjacent top shelf to collect two armor batteries. If you've been careful not to get injured much so far, your armor rating will now be 100. Leave the room and go down the nearby stairs, then go through the open fire door. Go through the next doorway, then turn left and run down to where a large door closes in your face, and the G-Man gives you his "you're not done doing my dirty work yet" look.
Get the shotgun out and go stand facing the wall that's directly across from the doorway you entered the room through. A vort will soon break through that wall, and you'll want to double-barrel it in the head as soon as it does. Run through the wall hole and turn right before the other two teleport-in vorts can see you, then move down the narrow passage to reach the Missing in Action chapter.
MISSING IN ACTION
Section of2a1: WEAK CEILING TILES AND BIG FANS
Go forward and crouch-walk to where you're under the lowest of the three big blue pipes, then turn left and go down the hallway. You don't have to worry about timing your way past the steam leak, and you can easily shoot the headcrab in the room ahead with the pistol before it sees you. When you enter the room, turn right and get out from under the pipe, then get your shotgun out.
Move forward to the room's central pillar, then charge and double-barrel the vort that teleports in a bit to the right of the pillar. Turn left and repeat with the second vort who teleports in. (Wrench power attacks also work well, but the shotgun is a bit easier to use for this.) Bash the crates near the second vort to find two armor batteries, then jump onto the green crate near the first vort to get some shotgun ammo.
In one corner near the central pillar are three pipes that you can run up to reach a vent shaft. Bash its grating off, then enter it and crouch-walk past the first floor grating you come to. When you reach the second floor grating, bash it and drop down to a room with a health pack and an AR clip on some shelves. Go through the door at the other end of the room to return to the two-vort area. Go back up the pipes and reenter the vent shaft, this time bashing and dropping through the first floor grating.
Crouch-walk along the ceiling tiles with night vision on until you come to a section of tiles where most of them look water-damaged. (Also, a tile on the left is missing, and some wires are going down through its hole.) You could drop down through the first weak tile on the right to end up on a desk with an armor battery, then carefully jump your way across the room to where you can climb a fallen vent shaft back up to the ceiling tile area, but I'll assume you don't need the battery and don't want to mess with the zappy water room.
From the start of the "weak tile maze," go two tiles forward on non-weak tiles, then turn left and cross the wires. Turn right past the wires and go forward until you reach the start of the fallen-down vent shaft segment, then turn right and cross the wires again. On the tile past the wires, turn left and go forward to the back wall, then turn right.
Quicksave now, since you have to make a quick run across two weak tiles in a row. What you want to do is uncrouch, then run onto the first weak tile and quickly jump over the second weak tile before the first one gives way. That's the end of the weak tiles, so move on to the two-fan area.
Crouch-walk onto the nearest beam that's above the first fan, and use it to reach the center. Turn left and quicksave, then take a running jump across the beam break to reach the beam above the second fan. If you fall into a fan and die, quickrestore and try again until you make it. Crouch-walk to the second fan's center, then turn right and crouch-walk along until you reach a large window sill.
Drop down to the walkway below the sill, then turn right and crouch-walk along the right wall while watching the periodic steam burst that comes from a pipe on the left. Crouch-walk past the burst when it's off, then keep going until you reach the big pipe with the constant steam leak. Turn left and stay crouched while going under that leak, and you should make it past both leaks undamaged.
Go over next to the big hole in the walkway that leads to a door and quicksave again. Try jump-crouching across the hole until you make it, then crouch-walk through the door and bash all the wooden crates on the left for ammo. If you're careful, you can get all the ammo and leave without getting the attention of the zombie that's busy with a dead scientist.
Crouch-walk to the end of the left edge of the walkway break, then turn right and take a running jump toward the railed balcony that leads to the second fan area. After quicksaving, crouch-walk your way carefully straight down the line between the two fans. Now *that's* scary! When you reach the railing in back, turn left and go forward until you can drop down to a lower floor through a railing gap.
Go over to a spot near the fan with only one blade, then quicksave again. As soon as the blade goes by in front of you, run toward the fan and crouch down. Drop gently through the broken grating beneath the fan so that you'll land on the big X-shaped thing right after section of2a1b loads.
Section of2a1b: FURNACE VENTS
Drop down to the bottom of the shaft, then crouch-walk along until you reach a couple of latticed gratings that you can bash out. Past them, quicksave before you try to jump over the furnace vent. Wait until a flame burst has fully dissipated, then quickly jump over before the next one comes along. Before you jump over the second furnace vent, get out the pistol and find the headcrab that's sitting on the ground to the left of a crate on the other side (using night vision can help you find it).
Shoot the crab until it's dead, then get out the .357 and go stand next to the wall just behind the stack of two crates. There's a mawman (advanced-stage zombie) in the area across the furnace vent and to the right. If you stand in the right spot and look through the gap between the wall and the two-crate stack, you'll be able to see the mawman occasionally lift its right arm. (Having night vision off may help you see the arm more clearly.) When its arm is up, shoot it. Keep that up until you see the mawman go down.
Jump-crouch onto the single crate that's next to the two-crate stack, then quicksave before taking a running jump across the furnace vent. It is possible to make it across without taking any damage if you jump when the vent flame is at its low point, so you might want to keep quickrestoring and trying again until you manage it (or until you only take minimal damage, which is -10 health and -20 armor).
Bash all the wooden crates to find a health pack and an armor battery, then bash through the latticed grating to find another crouch-walkin' tunnel. This one leads to a breakable floor lattice that'll drop you right next to another big furnace vent. Time your run past its flame, then quicksave while standing next to the second vent with the .357 out. You'll need to follow a flame burst down the vent to the left, then jump-crouch out of the vent on its right side and quickly crouch down next to the large pipe thing.
Head-shot both of the nearby mawmen to death, strafing if necessary to avoid the gook they throw at you. Or since the flame doesn't quite reach the large pipe thing, you could crouch down next to it without jumping out of the vent. From there, you can fairly easily head-shot the nearest mawman. For the second one, stand up to get its attention, then crouch back down and wait for it to come within head-shot range.
Switch to the shotgun and get on top of the pipe thing, then shoot down the regular zombie that comes your way. There's one more zombie left in the back of the area. Go over to where you can shoot it down with the shotgun, then check near the dead marine for an assault rifle on the floor and some hand grenades on top of a box that you can jump-crouch onto.
Look around in the area near the dead marine to find a pushable crated marked "DANGER EXPLOSIVES." Push it along to the left of the ramp it starts out near until it's in the furnace vent that's next to the sign warning against obstructing the test flame. Go up the ramp and find the "TEST FIRE" button. Move up against it, crouch down, and press it.
Stay crouched until the explosions have stopped, then get up and go back down the ramp to find a large hole in the floor nearby. Drop into the hole, then carefully move to where you can use the pistol to shoot the legs of a mawman without it seeing you. After it's dead, drop down to its floor, then move slowly ahead, shooting headcrabs as you see them.
After you go down a steep decline and reach the back of the area, find the break in the vent shaft to the right. Shoot the headcrab that's in it, then jump onto the concrete that's next to the shaft. Crouch-walk through the shaft break, then turn left and move forward to where section of2a2 loads.
Section of2a2: PIT DRONES AND ELEVATOR SHAFT
Around the next corner are two grate coverings that you can bash out and go through. Move along the concrete ledge until you drop down next to two more grate coverings, one of which has already been removed. Crouch-walk through it and forward to a dead marine with some AR grenades and shotgun shells near him.
After getting the ammo, crouch-walk back out and drop to the street below. Go down to where a dying marine warns you about the pit drones ahead, then go past the truck that's blocking a large door open. Jump into the back of the truck and bust open the two crates to find some shotgun shells and a C4 satchel bomb.
Past the truck, go through an open red door and down to Storage Area 2. Ignore the pit drones running past on the overhead walkway, and bash the crates to find a health pack. Just past the crate area are two large red doors with a button panel between them. Ignore that for now and go slowly down the dark hallway to the right of the doors with night vision on.
When you come to the first tall wooden crate, get out the pistol. Crouch-walk very slowly to where you can see an arm of a pit drone that's standing near another crate a ways past your crate. Sneak-shoot the drone in the arm until it falls over dead, then quickly strafe left and move up behind the second tall hallway crate.
The other pit drone in the area will go over to the first one (drones have the nasty habit of chewing on each other's dead bodies), so get to where you can sneak-shoot it to death with the pistol. After it goes down, bash all the crates in the hallway and in the drones' room to find two armor batteries.
Go back to the two red doors and use the button panel that's in between them to open up the one on the right. There are four pit drones in the garage area, and the safest way to deal with them is to sneak-shoot them all with the pistol. Carefully move to where you can sneak-shoot the first one, then strafe left for cover and wait a bit before trying to sneak-shoot the next one. Repeat the process until all four pit drones are dead.
NOTE: If you're very careful, you can get to where you can see part of a pit drone's head without it seeing you. You can then shoot it in its little cluster of red eyes to do more damage per shot and save on bullets, though this isn't really necessary, as there are plenty of bullets to resupply from in most areas of the game.
Jump into the back of the truck in the garage and bash the crate to get your first laser tripmine. Go up the stairs to the upper walkway and turn left to find an armor battery on the floor near a tool chest. Bash the crates on the other side of the walkway to find a C4 satchel and an RPG. Go up the stairs that lead to the next room very slowly, since there are two pit drones over to the left.
Use the usual process of sneak-shooting the first one with the pistol, then backing up and waiting a bit before sneak-shooting the second one. After both drones are down, enter the room and go over to the scientist who's hiding behind some tables. After he says he doesn't know which is worse, the marines or the aliens, answer his question by jumping over a table and splattifying him with a powered-up wrench whack.
Go over to the jammed-open elevator door and find the yellow ladder on the wall that's directly across from you. After quicksaving just in case, take a running jump toward that ladder. If you land on it, you'll automatically grab ahold of it without falling. Climb down it, then go across the narrow ledge to reach another ladder that you can use to climb down to the bottom of the elevator shaft.
Enter the crashed elevator car through its open door, then use its open roof vent to climb up onto the roof. Jump from there to the nearby jammed-open doorway to reach a room with a big fallen-over set of shelves. Go through the doorway to the left of the shelves and turn right to reach an area covered in super-slick water.
There's a live wire hanging down in the middle of the watery area, so you don't want to just slip and slide through. Quicksave, then very slowly crouch-walk toward the live wire. As soon as you can, turn left and edge around some crates in order to avoid the wire, then head for the crates in the back left corner. Jump-crouch onto the lowest crate, then jump-crouch onto the higher ones.
Drop down past them, then turn left and find the fence door that you can push open to enter the room with the unit 2 power box. Bash the wooden crates to find some .357 ammo, then use the switch on the power box to turn the electricity off. Go back down the hall to where you can jump-crouch over some crates and get back to the room next to the elevator shaft.
Drop back down to the bottom of the shaft, then climb up the two yellow ladders. Get off to the right from the second ladder, then go over to where you're directly across from a long, dangling power cable. Now that the electricity's off, it's safe to jump over to the cable and climb up it.
After you've climbed it to the top, look down at the nearby elevator car and climb down slowly until you're hanging just a bit higher than the car's roof. Swing the cable toward the car, then jump to let go when you're almost over it. You might could do that on the first swing without having to do a lot of swinging back and forth, though it's a bit safer if you swing a couple of times first.
Drop into the elevator car through its open roof hatch to find two armor batteries, then climb back up onto the roof. Go through the open elevator doors to find a dead fatguard with no pistol (dang him!), then turn left and go down the hallway until section of2a3 loads.
Section of2a3: A REUSABLE METAL CRATE AND SOME MARINE PALS
When you come to a locked red door, look on the wall nearby for a high-up vent shaft opening. Pull and/or push the small metal crate to where it's right under the opening. Jump onto the crate, bash the grating off, and crouch-jump into the shaft.
Move along the shaft until an explosion drops it down into the water. As soon as you exit the shaft, get out the pistol and turn around. Crouch down and strafe slowly right until you can see and shoot the fat, slimy leg of a bullsquid. After you kill it, go past it and walk around near the dead marine until you pick up a pistol clip and an AR clip.
Go back the other way until you find a big hole in the wall that you can go through. Turn right past the hole and go down to the red EXIT door and push it open. You'll be back in the area where you used the small metal crate, so push it through the open EXIT door and down the hall to the high-up vent that's near the wall hole you came through.
Use the crate to get up into the vent just like you did before, and explore it to find a dead scientist and an armor battery. Return to the hallway and push the crate over next to the left side of the big debris pile. Get on the crate, then crouch-jump onto the trash can. Get out your hand grenades and edge over to where you can throw a grenade through the broken window of the nearby room.
As soon as the grenade enters the room, strafe right to drop back down into the hallway. After the big explosion, push the metal crate through the blown-open room and over to yet another high-up vent opening. Use the crate to get into the vent shaft as before, then slowly move to where you can sneak-shoot a headcrab with the pistol.
Bash through the grate past the crab and drop down into a room with a sizzly-animated electric scientist on a desk. I always wanted one of those as a kid! Go out the room's door and turn right to find two big red doors that you can push open to return to the barricaded area near the blown-up room. Get the hand grenades from the small green crate near the room's windows, then check under the large leaning bookcase in the room for a health pack.
Go back through the red doors, then run down the hallway. Keep going until you reach a barricade with a health pack near it, then turn around and use the pistol to kill the headcrab that dropped from the ceiling as you ran by. Go back to where there's a hole in the floor and climb down its ladder (or just drop through it) to reach a room where a scientist is hiding.
Pick up the two armor batteries if you need them, then go to the back of the room and use the switch on the power box to de-electrify the cable that's hanging just above you. Jump to grab onto the cable, then climb it and swing it over the upper room's floor so you can jump to land on the floor.
Use the military radio that's next to a broken, knocked-over vending machine in a nearby corner, then bash the crate near it for a health pack. Look around the dead security guard for ammo and a C4 satchel while waiting for the two marines you talked to on the radio to blow open the maintenance door. After they do, go over and get the engineer to follow you.
Lead him to the door marked "ELEVATOR" and wait while he cuts it open. After he runs into the elevator, go get the other marine to follow you and lead him into the elevator. (Note that you'll have to talk to him again after you make it halfway there.) After they're both in the elevator, use its interior button panel to get elevated to the Friendly Fire chapter.
Section of2a4: VORT-INFESTED OFFICE AREA
After the elevator arrives on another floor, get out your shotgun and quicksave. Run straight forward to the dark alcove for cover, then peek out and blast vorts when it's safe to (or wait and shoot ones that run into your view). Hopefully, you and your marines can kill off the three vorts without your engineer getting killed. Quickrestore and try again if he dies.
If the engineer doesn't walk across the room and cut open the door marked "EXIT" on his own, get him to follow you over there. Past the door is a large cave-like area with a small security shed in the back. Enter the shed and get the ammo and armor battery, then go back to the cut-open door.
Look to the right of the door to see a metal machine box on the ground with a vent shaft going up out of it. You want to get up to the high-up ledge that the vent shaft is going up to, and the metal box is the way to start. Jump-crouch onto it, then turn right and use the sloping bits of dirt to jump up onto the ledge. Go over to its left side to find an armor battery.
Drop carefully back down to the cave room's floor using the dirt ledges, then leave the room and turn right after getting your engineer to follow you again. (If the other marine survived the vort attack, get him to follow you, too.) Go up all the stairs, then get out the wrench and hold it in power-attack mode as you run for the upstairs door.
A vort will crash through the door, so run up to it and give it a good powered wrench whack. Keep the wrench handy as you go through the door and slowly approach a doorway on the right. Let the vort past the doorway see you, then retreat and pull the wrench back for a power attack. As soon as the vort appears in front of you, let him have it! There's another vort past the doorway, in the office to the right, so get the wrench in power attack mode and go get him before he can whack or zap you.
The office area is now secure, so get the pistol from S. Jones' desk and the health pack from on top of a filing cabinet. Push open the red door that's down the hall from the office area, then move a very short distance past it to get two vorts to drop down. As soon as you hear the ceiling tiles give way under them, back up through the doorway and strafe left for cover.
Hopefully, your marine(s) will kill both vorts for you without getting killed. If not, quickrestore and try again, helping out with your .357 if needed. After quicksaving again, run into the room and straight for the door alcove on the right. You don't want the alien grunt who drops in to see you. Hopefully, it'll be killed by your marine(s). In any case, have your .357 ready to finish the aliens off.
Push open the brown double doors in the alcove, then quickly retreat back around the corner. You can then strafe in and out of cover, using the .357 to deliver careful head shots to the three vorts in the large meeting room. After they're down, move slowly along the room's left wall until part of it explodes. Use the .357 to sneak-shoot the vort that's in the space between walls, then do the same to the two vorts that are in the hallway past the big wall hole. (Note that the second one is in a sort of alcove on the left.)
After they're all dead, go down the hall to the EXIT sign to find a red door you can push open to return to the alien grunt drop-down room. Wrench-whack any surviving marines to get their guns, then return to the corridor where you shot the last two vorts. Find the side corridor that leads to a room labeled B-591FG. As you approach the room's doorway, section of2a5 will load.
Section of2a5: GETTING THROUGH THE LAMBDA SECTOR TRANSPORT DOOR
In the room past the doorway, check out the "EMPLOYEE OF THE MONTH" picture on one wall (it's meant to be Gordon Freeman), then jump onto the left side of the desk that's next to the big wall hole. Crouch down and move around to where you can crouch-jump through the wall hole, then run up the two slanty pipes.
Turn right and run up the curvy vent shaft to reach the next floor, then move slowly toward the dead scientist with night vision on. There's an armor battery near him, but there's also a barnacle tongue that you'll want to avoid. Jump over the hole in the floor to get to the side with a ladder on the wall, watching out for another barnacle tongue near it.
Climb the ladder to reach a metal walkway with a big break in its center. Jump across the break on its right side to avoid a barnacle tongue, then go through the door and crouch-walk along the left wall until you can see into the big room that's to the left. Get to where you can see a stack of explosive crates on the other side of the room, then shoot them with the pistol until they explode. That'll destroy the alien grunt that's standing next to them.
Get onto the nearby walkway piece, then turn right and slowly crouch-strafe your way left with night vision on until you see the second grunt on the walkway that's across the room. Stand up and hit him with a carefully aimed RPG rocket, then switch to the .357 to finish him off. (If he starts running around on the walkway, either quickly shoot him down before he sees you, or run back around the corner for cover and sneak to where you can shoot him unseen.)
The RPG rocket should have also blown up all the sizzly electrical nodes that are nearby. If not, shoot one of them with the pistol and wait until they all explode. You can now swing across the big walkway gap using the two dangling power cables. After quicksaving, take a running jump to the first cable, then jump to the second one when you swing close to it, then jump to the other side of the walkway when you swing close to it. You should make it easily, and without having to do any annoying back-and-forth swinging.
Get the hand grenades and AR grenades from the big broken-open crate, then bust open the other two crates to get bullets and .357 ammo. Down the walkway past where the second grunt was standing is a lift. Use the button panel on the wall next to it, then quickly run onto it before it starts going up. In the room ahead, use the military radio and listen to the message while collecting ammo and blowing away houndeyes with the shotgun.
When you're sure you have everything, go up the ramp to the left of the radio and blow away one more houndeye before jumping onto the large slanty beam. Run up that beam to where a skinny beam is lying across it. Jump onto the skinny one and go up it to get onto the pavement. Go over to the big "ORDINANCE STORAGE FACILITY" sign and look to the right of it for a broken-open vent shaft that you can crouch-walk into.
When you reach the shaft junction, turn left, but don't go forward to the grating. Instead back up to where you can stand up. After quicksaving, shoot out the grating with the pistol. Hopefully, the black ops guys who are standing and talking just past the grating won't notice. If they do, quickrestore and try again. If they don't, crouch-walk to where the grating was, toss a C4 satchel, then back up and detonate it to blow up both black ops guys.
Crouch-walk out of the shaft and up to the back of the truck. Place a tripmine on the back of the truck's right wheel, then return to the vent shaft. Go to the back part where you can stand up, then jump up once to get the attention of another nearby black ops guy. If you crouch down and wait, he should run into your tripmine and get blown up. Quicksave, then crouch-walk around to the right side of the truck. Turn to face the truck, then crouch-strafe slowly to the right while looking under the truck at the area in the distance.
When you see a black ops guy, sneak-shoot him once with the pistol without letting him see you. He should run a little to the left, exposing part of a door with a board across it. Strafe a little more to the right if you need to, then shoot the board with the pistol until it breaks. The door should swing open and detonate a tripmine, killing the black ops guy. If it doesn't work, quickrestore and try again. (Or try sneak-shooting the black ops guy some more to see if he'll run into the tripmine after the door opens.)
There's a second black ops guy down there that the tripmine probably didn't kill, so crouch-walk under the truck and over to where you can sneak-shoot him with the .357. (He may have walked over to the doorway with his back turned, making it really easy for you.) Go through the doorway and around to where a turret has been set up. Give it a good powered-up wrench whack to knock it over.
Go through the door that's past the turret's little laser alert, then go up to the medic who's standing around outside. After he's through talking to you, get him to follow you, then go back through the door to the turret area. Go on around to the main room, then cross it to find several wooden crates you can break open for ammo and health packs.
After you do that, find the large door with the working button panel to the right of it. Hit the button to open the door, then go through it and bust the two crates to find a C4 satchel and another health pack. Wait while your medic heals the wounded engineer, then get both of them to follow you. Lead them all the way through the turret area and back outside, then leave the medic standing near the turret area door.
Go across the pavement to the sealed "SECURED ACCESS: LAMBDA SECTOR TRANSPORT" door and wait for your engineer to start cutting it open. Get out your .357 and quicksave when he's nearly done, since you don't want him getting killed by the turret that's past the door. As soon as the door falls, start firing at the turret. You should be able to take it down before it can kill your engineer. If not, quickrestore and try again, remembering exactly where the turret is and positioning yourself accordingly.
After you manage to save the engineer, go past the downed turret and to the right to find a C4 satchel. Look down the nearby hallway to see a couple of set tripmines. Back up to where you can just barely see the nearest tripmine, then shoot it with the pistol and quickly strafe left. Get your medic and engineer following you again, then head down the formerly tripmined hallway to reach section of2a6.
Section of2a6: ASSASSIN ROOM AND HUGE BLACK OPS BATTLE
Hopefully, both the medic and engineer will follow you into this section without glitchily vanishing. Leave them both somewhere on the stairs, then approach the two new marines who are waiting just past the stairs. After they finish talking to you, get them to follow you so you can leave them on or near the stairs, completely out of sight of the big doorway they start out next to. (This is to make sure they don't see any of the assassins that you're about to stir up. You don't want any of these guys getting hurt yet.)
Cross the rail track and approach the large open doorway that leads to the room with big blue storage bins and tall wooden crates in it. Crouch-walk over to the left side of the doorway and set a tripmine in the approximate center of the doorframe so that the laser goes across the doorway. Get the pistol out and turn night vision on, then quicksave.
Fire the pistol at anything to get the attention of one of the assassins, then go snuggle up in the corner that's a bit to the left of the doorway. The assassin who heard your shot should eventually walk into the tripmine and get killed. Get out your .357 and wait for other assassins to walk up to the doorway and stop.
As soon as you see one, shoot her in the head for an instant kill. If one sees you and runs off, be ready for her to run back into view and shoot at you, at which time you should quickly finish her off. If this happens too often, you may want to quickrestore and try the whole thing over again.
You can quicksave and then quickrestore at any time during the process to cause all moving assassins to "freeze" in place. You can then slowly move to where you can sneak-shoot them. It's best to quicksave every time you hear an assassin approaching the doorway. That way you don't have to look very far for her if she sees you and you have to quickrestore.
After you kill four assassins, you should stop hearing the patter of their little feet, meaning no more are moving around. There's just one assassin left. Crouch-walk through the doorway on its left side, then turn left and move forward very slowly until you can see and sneak-shoot the assassin with the .357. (Note that if you used the quicksave-and-quickrestore trick, you may have to hunt down more than one leftover assassin.)
After they're all down, find the stairs in the back right corner of the room and go up them. At the other end of the upper walkway is a switch. Use it to open up a nearby section of track, then go back to where you left your four marines and get them all to follow you. Right after you cross the track again, turn right and go down the long pathway that goes along the left side of the track.
You'll eventually reach a side room with several boxes you can break open for supplies. Make sure all four of your followers are still with you, then make a regular save. Not only is the big black ops fight sequence ahead tough to get through without serious injury, but it's also *the* number one most endlessy fun and replayable part of the entire Half-Life game series (in my unhumble opinion, anyway).
Move on to where you can cross the track again, and do so by crouch-walking along the left side of the crossing area. Have the .357 out and night vision on so you can see and quickly shoot a black ops guy in a doorway a ways ahead. After he's dead, hang back and see if any assassins will walk over to where you can shoot them. (Or if some of your squad runs on ahead, follow them and offer supporting fire.)
After that hallway is clear, check the large right-side room to find a PCV recharger and some boxes on shelves that you can break open for ammo. When you round the corner at the other end of the hall, take cover behind the wooden crate on the right and shoot black ops guys from there. (Maybe launch an AR grenade at them if your guys haven't run down there yet.)
After the track area looks clear, crouch-walk across the track and to the start of the second hallway. If the black ops guys in that hall are already stirred up, you'll probably want to hang back and let your squad handle them while you help out with the stragglers. If the hall is quiet, fire an AR grenade at the window that you can partly see over the wooden crate that's near the start of the hallway to stir things up.
When that hallway looks clear, crouch-walk slowly over to the doorway that leads to the large right-side room. There may still be one or two black ops guys in there. One way to find out is to toss a hand grenade or two into the room and see if any black ops guys run out. If so, quickly shoot them down with the assault rifle. When the room is clear, search it for an armor battery and some supplies in boxes on shelves.
The room at the end of the hall almost certainly has a leftover assassin or two in it, so try to sneak-shoot them with the .357. If they're not in the room, they may be past the top of the stairs in the back of the room. After they're all down, the area is secure, and you can relax and look around for supplies. Also, go along the walkway past the stairs to find a switch that you need to use in order to open up a section of track.
Look all around for supplies, and use the PCV recharger in the first hall's side room if you need to, then dispose of your surviving marines so you can grab their weapons. If there's more than one left, have them all stand and wait in one area, then get one to follow you to a far-away spot where you can whack him with a wrench power attack. Be *sure* to pick up the powerful SAW machine gun that one of them has. If he was killed earlier, look all around until you find his gun.
If you have trouble with the other marines always turning hostile and attacking you after you whack one of them, you'll have to kill all of them except the last one (who you can wrench-whack) by running over them with the rail car. Lead them one at a time to the track area in between the hallways, then tell them to stay put when they're right behind the rail car. Get on the car and use its control panel to back up until the marine dies, then stop and move the car back to its original location. The only problem with this is that the marines' dropped weapons may be hard to get to without getting zapped by the electrified rail.
When you're totally done with the area, get on the rail car and back it up until you're past the rail path split with the spinny arrow gadget on the wall. Shoot the arrow gadget with the pistol to switch it, then move forward in order to go down the right-hand track. Crouch down to duck the dangling live wire as you round the first corner, then stand up and watch for a secure door ahead. As you approach it, slow down and start looking to the left.
Stop when you can see part of a small sandbag wall, then back up a bit. Leave the rail car and crouch-walk slowly along the left ledge until you can sneak-shoot the black ops guy who's near the sandbag wall with the .357. After he's down, go over to the broken window with the big round beam sticking through it. Crouch-jump onto the window sill, then drop down on the other side and crouch-walk over to the right to find a supply area.
After you thoroughly raid it, crouch-walk over to the metal barrel (careful not to get zapped by the dangling live wire) and push it to where it's next to the large fallen beam. Jump-crouch onto the barrel, then crouch-jump from it to the beam. Keep as far to the right as possible as you go up the beam and past the live wire. (It's best to wait until the wire is twitching to the left before moving past it.) Turn right when you get up onto the ceiling and go forward to find a vent grating. Bash it off, then go through it and on to where the We Are Not Alone chapter starts.
WE ARE NOT ALONE
Section of3a1: LAMBDA TELEPORTER CHAMBER
After you exit the vent shaft, turn right to find first aid and HEV stations on the wall. After recharging, go to the other end of the hall and quicksave. Use the button panel to the left of the big doors to open them, and watch as Gordon Freeman makes the jump to Xen. Turn right and run around the chamber until the gate-opening scientist's platform falls down ahead of you. Jump-crouch onto the low end of the platform, then run and jump up to the top to hit a teleporter that'll take you to a different part of Xen, where section of3a2 starts.
ALTERNATIVE: After you open the doors to the teleportation chamber, you could stay near them and dodge alien controller fire while waiting to see if any of them are killed by the teleporter's explosions. Then hide around the corner for cover and use the pistol to shoot down all of the rest. Charge back up to 100 health and 100 armor at the wall stations, and go back to the big black ops battle area to resupply on bullets. (It's possible to go all the way back to near the beginning of section of2a2, but that would be ridiculous.) Return to the teleport chamber and go use the teleporter described in the previous paragraph. You'll arrive in Xen with full ammo and without any damage at all!
Section of3a2: BORDER WORLD EXCURSION
Jump from the rocky platform you start on to the nearby one that has a dead HEV guy and an ammo canister on it. Pick up the canister, then walk over to the big alien whoosh-thing that's on the ground. You'll want to use it to jump to the higher rocky platform that's just to the left of the one with the yellow zap-crystal and the purple orb.
Once you know where you want a whoosh-thing to blow you, stand on the opposite side of the whoosh-thing from the target area, then run onto the whoosh-thing and lean on the "Move forward" key until you land. If that doesn't work, try jumping as you run onto the whoosh-thing. And do always quicksave first, just in case something goes wrong.
Right after you land on the new platform, a scientist and a fun new weapon will drop down onto a nearby platform. Jump over there and grab the displacer gun, which has two firing modes. The regular-fire mode works like the BFG in DOOM and Quake, and the altfire mode works like a dis-or-dat teleporter. If you're in Xen when you use it, you'll be teleported to somewhere in our dimension. If you're in our dimension when you use it, you'll be taken to a spot in Xen.
At the beginning of each section from now on, I'll put in a displacer note (like the one below) describing the area that using the displacer's altfire mode anywhere in that section will take you to. That's not to say that you should use it in every section, especially since each altfire teleportation takes up 60 units of ammo. You can decide from my detailed description of each destination (and the availability of displacer ammo) whether or not you want to go there at any point.
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to the jump-crouch room in the Black Mesa hazard course area. Run up to the rail that's just ahead of you and use the shotgun to blow away the nearby vort while it's attacking the instructor hologram. Turn and crouch-walk your way under walkways until you reach the other end of the room, then shotgun-blast the vort that's down there. Return to the starting area and jump-crouch over the rail, then make your way through the three jump-crouch pipes to reach the other side and claim a shotgun from next to a dead security guard. Jump onto the railing that's a bit to the right of the nearby door, then jump-crouch from it to the higher railing. Get to where you can smash a window, then go through it to enter a room with a bulletin board (notice the picture of the freaky horrid-head guy on it), a first aid station, and a teleporter that'll return you to the rocky platform where you got the displacer.
Jump to the other nearby platform that has a whoosh-thing on it, then look around to see where it can take you. There's one higher rocky platform over to the left that's kind of off by itself, so it's not a good place to go. Look over to the right to see two higher rocky platforms that are close enough to each other that you could jump from one to the other. Use the whoosh-thing to get to the rightmost of those two platforms. From it, you'll be able to jump across to a platform with another whoosh-thing and two houndeyes on it.
Blast the houndeyes with the shotgun right after jumping over (or with the pistol right before jumping over), then look up to see the teleporter orb that you're going for. You could use this whoosh-thing to jump straight at the orb, then use the movement keys to make sure you fall into it, but an easier way is to whoosh up to the rocky platform that's just to the left of the orb, then run off of it and drop into the orb. Either way, you'll be teleported to the Crush Depth chapter.
Section of3a4: PIT DRONE DETOUR
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large healing water area in Xen. There are two bullsquids slurping up the water, but they won't attack you even if you attack them. After you get back to 100 health by standing in the water, find the large tunnel that leads to an area with two armor batteries and a teleporter orb. Use the orb to return to a spot in the hallway near the lift mentioned in the paragraph below.
Use the button panel on the wall to the left of the nearby doors to open them, then get on the lift and use its button to descend. Leave the lift and go right in the hallway. Push through the glass in some broken doors, then move on to reach a room where a scientist has stranded himself to escape two pit drones.
They're both on the other side of the large control panel that's to the left. Edge carefully over to where you can use the pistol to sneak-shoot one of the drones over the left edge of the panel, then crouch down for a few seconds before doing the same to the second drone. (Remember that the other drones in a group will usually walk over to chew on a drone that you shoot down.)
After they're both dead, use the big yellow button on the control panel to teleport the stranded scientist into the room, then use the first aid and HEV stations on the wall if you need to. Get the scientist to follow you, then go all the way back to the hallway next to the lift. Go to the other end of the hallway to find a room with a retinal-scan door. Wait near it until the scientist opens it for you.
Crouch-walk slowly past that door until you're in position to sneak-shoot the bullsquid that's in the hallway ahead with the pistol. After it's dead, check the shelf near it to find three packs of displacer ammo. Pick up what you can, then jump into the broken fish tank and climb up to a spot near the top of the ladder.
Get the displacer out and turn to face the higher walkway nearby. Aim at the center of the ceiling over the walkway's left half and fire off a regular-fire blast. As soon as the blast is away, look down and run forward to exit the fish tank and avoid damage. Pick up another displacer ammo pack (if you didn't get them all earlier), then repeat the process, targeting the right side of the higher walkway.
If your aim was good, there should only be one or two pit drones on the walkway over on its right side. After you climb the ladder, turn left, run over to the wall next to the walkway, and crouch down. If you turn night vision on, you should be able to back up slowly and shoot the drone(s) on the walkway in the head with the pistol without them being able to do anything about it.
Pick up the nearby bullet clip if you haven't already, then go over to the other side to find a health pack. To get onto the upper walkway, run up the fish tank's open top. Make sure the left part of the walkway is drone-free, then crouch-walk carefully up to the big crack in the wall. Sneak-shoot the drone that's behind that crack, then get out the shotgun and walk on past the crack backwards.
When you reach a certain point, part of the ceiling will collapse, and a pit drone will drop down and attack if your displacer blasts didn't kill it (though they should have). If a drone does drop down, quickly kill it with the shotgun. Get the pistol back out and crouch-walk up to the large hole in the wall near its end. Sneak-shoot the drone that's standing near the other side of the hole, then crouch-strafe to the right until you can sneak-shoot the final drone through the hole.
Get the .357 from the dead fatguard nearby, then go all the way back to where you used a control panel to free a scientist earlier. Use the wall stations there to get your health and armor back up to 100 each, then return to the pit drone area. Go through the wall hole and down to where you can crouch-walk into a large vent shaft opening. Move down the shaft until section of3a5 loads.
Section of3a5: SCREWY TELEPORTER AND ICHTHYOSAUR TANK
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to an area in Xen where you'll experience a fatal fall. There's nothing you can do about it, so don't go there.
At the end of the vent shaft, bash through the grating and drop into the room below. Go to the other end of the room to find two packs of displacer ammo, then enter the big teleport chamber in the room's center. Use the button panel in the back of the chamber to start up a screwy teleport sequence. Wait until you're teleported into the nearby water, then swim through the square hole in the wall.
After you surface, go around a couple of corners to let two zombies and a headcrab see you. Run back to the underwater part of the ramp and crouch there. As long as you're underwater when crouched, the zombies will walk up to you, but will be unable to hit you. Kill both of them with the knife, then wait for the headcrab to come underwater and try to leap at you. It'll probably miss, and you can easily knife it to death.
Go down the corridor to a room with another zombie in it. Get its attention, then lead it back to the water and repeat the underwater leg-slashin' routine to kill it. Return to its room and use the pistol to sneak-shoot the headcrab that's hiding behind the blue machine, then bash out the grating over the room's vent shaft. Move along the shaft until you fall down into a large pool.
Swim over to where you can climb a short ladder to get onto a concrete walkway, then move slowly down the short blue-lit hall. The room to the right of it has two headcrabs, a zombie, and a mawman in it. You'll want to move to where the headcrabs and zombie see you, then quickly back up and shoot them with the pistol (headcrabs) and shotgun (zombie) as they come after you.
Get out the .357 and turn night vision on, then carefully sneak over to where you can sneak-shoot the mawman. When you do, it'll run forward a bit and see you, so quickly head-shot it until it goes down. In its room, get onto the small metal platform and head-shot the two zombies on the floor below with the shotgun.
Drop down to their floor and use the HEV station if you need armor, but don't try using the fizzly first aid station. If you need health, look for a health pack under the metal platform. Drop down through the large square hole in the floor to reach an area with two windows observing an ichthyosaur tank. Use the wheel that's near the right end of the right window to open the tank's door, then wait for the ichthyosaur to swim out through that door. (Unless it's stuck in the tank, which sometimes happens.)
Use the ladders to climb back up to the mawman's floor, then go outside to the concrete walkway area. After quicksaving, drop into the water, then turn and quickly swim for the open ichthyosaur tank door. If the 'saur left its tank, it should be easy for you to swim through it without getting damaged. If the big fish is stuck in the tank, you'll have to try to swim by it.
When you reach the room past the tank, use the wheel to close the tankside door and drain the water out of the room. (You may need to lean on the "Jump" or "Swim up" key to keep your head above the water as it drains.) Right after the water finishes draining, section of3a6 will load.
Section of3a6: SHOCKTROOPER AND SHOCKROACH
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to an area in Xen with several small rocky platforms. Don't try to get to the two higher ones with teleporters on them, but instead look around for the one that's next-highest to the one you start out on. It also has a few rocky spires and a bright yellow crystal formation. After you drop down to it, look around to find that you have two choices as to where to go next. Face the lower platform with the exit teleporter on it, then look to the left for one route and to the right for the other route. The left route has two armor batteries on its first platform, and the right route has one armor battery and a health pack on its second platform. Either way, you can get a health pack, an armor battery, and an ammo canister from the platform with the exit teleporter. It may take you to the hallway that's past the area with the shocktrooper combat, thereby skipping it, which I don't recommend doing. If you want to visit this Xen area, wait until after you kill the shocktrooper and get the shockroach weapon.
Ignore the big button in the control room and go around the corner to the hallway that's electrified in the middle. Get out the pistol and shoot the control box you see on the wall at the other end of the hallway. One shot will make it explode, and the electrical hazard will be removed.
Before you enter the next room, get out the SAW machine gun (it's under weapon category 6) and quicksave. As you go through the doorway, a pit drone will teleport in a bit ahead of you. If you back up and go around the corner fast enough, it may not see you. However, it probably will, so shoot it down quickly when it comes after you. The other pit drone and the shocktrooper probably won't have seen you since they teleport in a bit later.
Sneak-shoot the drone with the pistol, then get out the .357 and try to sneak-shoot the shocktrooper with it. It might see you, but that's okay, since its shockroach blasts will probably just hit the doorframe. Quickly shoot the shocktrooper in the head until it dies, then run into the room to pick up its shockroach. (If you do manage to sneak-shoot the trooper unseen, it may run into the next hallway, so look for it there.)
Be sure to get rather than kill the shockroach, since it'll come in real handy soon. Get the displacer ammo from the table and floor if you need it, then go down a short hall to reach some airlock doors. Go through the first airlock door and use the button panel on the wall to close it and open the second door.
In the next hallway, get the displacer ammo from near the dead scientist if you need it, then jump into the teleporter orb. That'll take you to a spot in Xen with several rocky platforms, but the only one you can safely get to is the nearby one with the exit teleporter. The others are part of the diplacer altfire destination.
NOTE: This is a good time to use the displacer's altfire mode to visit those other rocky platforms. (Even though you're already in Xen, using the displacer will still take you to another platform in the same area.) Use the displacer note at the beginning of this section to decide which way you want to drop down, then pick up the displacer ammo in the hallway when you return to it. Also, use the airlock doors to go back to the room where you killed the shocktrooper to get more displacer ammo.
After you jump into the other portal in Xen, you'll appear in another part of the hallway that's past the airlock doors. Use the button panel in the corner to open the nearby door, then go through to find yourself on a broken walkway with an unopenable door at the other end. Drop down into the water and crouch-walk around until you find the hole that leads into the ichthyosaur tank.
What you need to do is swim through that hole, then swim up to the top of the tank and find the bottom of a vertical shaft. Break through the grating in the shaft, then swim up to a water-logged hallway. (Note that you can easily locate the shaft before entering the tank by looking through its big windows.) Once you know exactly where the shaft is, it's pretty easy to go for it without having to worry about the two ichthyosaurs in the tank getting you.
That's your best route if you didn't get the shockroach earlier for some reason. If you did get it, stand on the edge of the walkway break on the side nearest the door you came through. Fire electric blasts at the spot in the water that you know the big hole is next to when an ichthyosaur is swimming near the hole. It can take awhile, but you can splattify both monster fish that way. Fun and easy!
After you swim through the fish tank and emerge in the watery hallway, go down it until the Vicarious Reality chapter starts.
Section of4a1: VOLTIGORE IN BIODOME 01
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large cave in Xen with a live scientist and a healing pool. You can get the scientist to follow you and lead him into the exit teleporter, but it won't do any good. Just heal up at the healing pool and use the exit teleporter to get to the secret armor battery room described three paragraphs below this one. (Or in game versions 184.108.40.206 and later, to get back to about where you were when you used the displacer's altfire mode.)
Go down the hall until you reach a large fallen-down pipe-like thing. Crouch-jump onto it, then crouch-walk up it and turn left. Jump onto the nearby ledge, then use the shockroach to kill the headcrab that's on the walkway. Jump-crouch onto the narrow upper ledge, then go over to the walkway railing and jump over it.
Get the .357 from the floor next to the dead fatguard, then use the shockroach to kill the headcrab that you can see at the top of the stairs ahead. There's another headcrab at the top of the opposite set of stairs, so go to where you can see and zap it to death, too.
At the top of those stairs, crouch-walk carefully onto the extremely narrow ledge that runs underneath the two nearby windows. When you reach the second window, stand up and break it with something, then crouch-jump through it to enter a small room with an armor battery. Crouch-jump back through the window, then drop down to the area below. Get back up onto the walkway the same way you did before.
Go up the other set of stairs and then run backward as soon as the headcrab over to the right sees you. Have the shockroach ready to quickly zap it to death, then go on down to the door that leads to a long hallway. A shocktrooper and two pit drones are going to teleport into this hallway soon, and you'll want to have an explosive surprise ready for them.
There are two sets of windows with big blue signs between them. Go to the first set (the one nearest where you entered the hallway) and deploy two C4 satchels. Toss the first one while facing the left window, and the second one (using the altfire key) while facing the big blue sign. The satchels should land next to the wall right under the center of the window and the center of the sign (or very close to that).
Run down to the other end of the hallway and press up against the door to get an "I'm locked" noise, then turn around and go back the way you came. Freeze as soon as you hear the first teleporting sound, then detonate your satchels right after you hear the third teleporting sound. Both drones and the trooper should be totally splattified by the explosion. The trooper's dropped shockroach won't be, so either wait until you hear it die or go zap it with your shockroach (or go pick it up if you missed the first shockroach-getting opportunity).
The shocktrooper broke the window it teleported in next to, so crouch-jump through it to get into the biodome 01 area. Move slowly toward the open rock door you see in the back of the area, and quickly dodge behind the nearest big rocks on the left when a voltigore teleports in.
It may try to run around the rocks to get to you, but it'll probably get stuck if it does. In any case, you're a lot faster than it is, so use that fact to dodge its displacer-like blasts and zap it with the shockroach until it blows up. Go through the open rock door and press the button to the right of the next door to open it briefly. After you go through it, use the button on the right wall to lower the lift and start section of4a2.
Section of4a2: BIODOME 02 AND THE SPORE LAUNCHER
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to another rocky platform area in Xen. In this one, you need to jump to the nearest rocky platform, drop to the next one to get an ammo canister, then jump to the last one to get an armor battery and use the exit teleporter. You'll end up in the room that's just past the little starting lift, or maybe in a spot farther along (depending on where you were when you used the displacer's altfire).
Get on the lift and get the .357 out, then turn and use the button to raise the lift. Crouch down and move slowly into the doorway after the door opens. Sneak-shoot the mawman that's over to the left, then quickly finish it off with head shots when it charges you. If the door closes before you can kill it and go through, use the buttons to lower and re-raise the lift.
Past the door, look to the right to see three small animal cages on a table. Using the shockroach, shoot the doors off of the two cages that have them, then kill the headcrab and houndeye that are in the cages. Go over to those cages and turn around to see three more headcrabs to zap, one of which is on the head of a dead scientist. You can use the left button on the control panel to the right of the door to open the bullsquid's cage and kill it, but I wouldn't bother.
Go through the door and down to another door, which will get you back to the long hallway in the previous section. This is useful if you want to go back for leftover supplies. Return to the cage room in this section and go over to its other side to find two more glass-fronted cages. The right one has two snark packs in it, so use the right button on the nearby console to open the cage, then jump into it to collect the snarks.
Go around the corner opposite the snark cage to find a door that leads to another hallway. Use the first aid station to the right if you need to, then go down the hall to find two doors marked "STORAGE." Bash the three little boxes near the door on the right to find an armor battery. Open the left storage door, then quickly back up and zap the headcrab inside with the shockroach. Go in to find three displacer ammo packs, plus several boxes you can break open to find two more armor batteries.
At the other end of the hall are some damaged elevator doors. Break the glass out of the top part of the right door, then jump-crouch through. Climb up onto the elevator car's roof using its open roof hatch, then climb up the long ladder that goes up the back of the shaft. When you get up near the top, quicksave, then carefully move off the ladder onto the right-side ledge.
That can be very hard to do without falling, so quickrestore and try again if you have to. Once you make it onto the ledge, quicksave again, then run (don't jump) toward the fallen-over door you can see sticking into the shaft a bit below you. When you make it safely into the hallway past that door, quicksave again.
Go down the hallway and turn left. Go through a door and then another one, then move ahead to where the hallway splits. If you continue ahead from there, you'll get a brief preview of section of4a3, but there's nothing you can do there now. So instead take the hallway branch that leads to a very quiet elevator that you can summon and ride down to a new area.
Go over to the control room door and get out the .357, then quicksave. Push up against the door to open it, then immediately back up while shooting the pit drone that's directly ahead of you with a couple of quick slugs, then strafe right for cover until the door closes. If you're fast enough, the drone won't be able to hit you with any of its sharp tooth darts. Keep that up until the drone is dead. (Note that it may come through the door after you, but that's very rare.)
Crouch-walk through the control room door, then move to where you can see the second drone up on the raised floor on the right, but it can't spit teeth at you. Zap it with the shockroach until it's dead, then crouch-walk to the back of the room and around to the base of the big ramp. Carefully move to where you can see the pit drone at the top of the ramp, then stand up and sneak-shoot it to death with the pistol. (Note that it may be walking down the ramp as you approach, but that's another bit of very rare behavior.)
Go up the ramp to find an armor battery on a table, then consider going for a secret stash of snark packs. It's a bit of a pain, and snarks aren't all that useful, but I'll describe how to get them in case you want to. Go back down the big ramp and over to where you can see an open red-lit vent high up on the wall near a corner. That's where the snark packs are hiding. To get up there, you'll need to use an item to help you jump onto the top of the shorter of the two computer banks that are next to the wall with the open vent.
The handiest item (if it hasn't gotten broken) is the chair that's next to the nearby desk. It's kind of hard to get it to move, so try getting between it and the desk and pushing it. If that chair got broken, use the one that's on the upper floor past the big ramp. If that one's also broken, you'll have to set a laser tripmine on the shorter computer bank to use as a stepping stone. (Unless you're playing version 220.127.116.11 or later of the game, in which case tripmines can't be used as stepping stones anymore.)
Once you push a chair up next to the shorter computer bank (or set a tripmine on it), you can jump-crouch onto the chair (or tripmine), jump onto the shorter computer bank, then jump onto the taller computer bank. From there you can easily climb the open vent cover and crouch-walk into the vent. After you go in a short distance, several live snarks will drop into it and start attacking you. They all drop down at a point that's directly between the two snark packs and just below them.
Get out the pistol and quicksave, then move far enough forward to get the snarks to start dropping in. Quickly shoot the first one while backing up a bit, then rapidly shoot the others as they appear. If you get injured, quickrestore and try again. With a bit of practice, you'll be able to kill them all without getting hurt. (You could use the assault rifle for continuous fire to make things much easier if you don't mind using more bullets.)
Get the snark packs and drop back down to the floor (using the computer banks to avoid health damage), then go up the big ramp and break out the cracked glass in the large window. Move into the window far enough to see a bullsquid on the ground far below, then kill it with the shockroach while dodging its toxic spit.
After it's dead, crouch-drop onto the ledge below, then turn left and crouch-walk your way along until you reach a wide concrete ledge. Stay on it and use the shockroach to kill all of the houndeyes running around. (A funner but slower way to do that is to stand in a spot near a spiky plant so the houndeyes will run too close to it and get hit. Zap the plant with the shockroach to encourage it to keep swinging.)
Drop down to the ground and stand in the small healing pool if you need health, then go under the open rocky door. Use the button to the right of the next door, then go through it and ride up the small lift just like you did the identical one at the beginning of this section. In the room beyond the lift, go pick up the big green spore launcher weapon, then return to the lift and ride it back down.
Go back into the biodome and locate the three green alien plants that are on the ground next to rocks. Run up to each of those plants to pick up the spore pods that they contain, then return to the first one you visited. Wait for it to grow a new pod, then get it and visit the other two plants again. Keep this up until you can't pick any more pods up. (You can monitor your pod inventory by having the spore launcher out.)
NOTE: You can use the biodome's whoosh-thing to get back through the big window you dropped down through. Stand on the side of the whoosh-thing that's directly opposite the window, then look up at the window as you run onto the whoosh-thing and jump. Lean on the "Move forward" key until you land safely on the window's sill. This can be useful if you want to go back for leftover supplies.
After your spore launcher is full of pods, go back to the room where you got it and find the hall that leads on from there. The door on the right side of the hall is another way to get back to previous areas, so ignore it unless you want to do that.
There's a mawman in the room at the end of the hall, and the best way to fight it is to let it see you and then lead it back to the room where you got the spore launcher. It should get stuck at some point in the hallway or near the broken aquarium container. If it does, hit it in the head with regular-fire pods while dodging its thrown gunk until it's dead. If it doesn't get stuck, dodge around and quickly switch to the shotgun to blast it with.
Reload your spore launcher, then take the lift back down and go outside to resupply on pods. (You could use the plant in the terrarium in the mawman's room, but it would be slower that way.) Return to the mawman's room and go through its door, then keep going along until you reach section of4a3.
Section of4a3: BARNACLE WEAPON AND BIODOME 03
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a rocky platform area in Xen that's nearly identical to the one in section of3a6 in the previous chapter. There will be no higher platforms that you can't reach, and there won't be a health pack near the exit teleporter, but otherwise it's just the same. Using the exit teleporter will put you in the hall at the beginning of this section, or maybe in a spot farther along (depending on where you were when you used the displacer's altfire mode).
Before you reach the two windows down the hall, use the shockroach to break the glass out of the nearest one. Crouch-walk up to it, then crouch-jump onto its sill. The houndeyes in the room below will see you, so quickly shockroach them to death before they can fire off any sonic blasts. Drop into the houndeye room and go through the door on its other side. In the next room, use the big red button on the control panel to view a holographic message that a scientist left for someone named Walter.
After the message is over, you'll be able to go through the door at the other end of the room. Go up to the case with the barnacle in it to pick it up, then go through the next door to reach a room with two test-firing-style chambers that have creatures in cages at their other ends.
To release each creature, use the button panel that's just to the right of its chamber. This is optional, but you can have fun using the barnacle weapon to pull in and chew up the headcrab. (Note that with the houndeye, you'll need to jump into the chamber so the barnacle can pull you to the houndeye.)
Get the armor battery from the table if you need it, then get out the shockroach and go over to the door that's to the left of the table. Press up against the door to open it, then quickly fire off a few zaps at the pit drone that's directly across the room, strafing left to avoid its tooth darts. After it's dead, open the door by right-strafing into it, then sneak-shoot the pit drone that's to the left of the door with the shockroach.
There's one more pit drone down in the room's central pit. You could try to kill it by shockroach-zapping several of the alien plants in the room to get them to spit their pods all over the place, but a more reliable way is to move forward to where you can zap the drone, backing up whenever you need to dodge its tooth darts.
After it's dead, get out the barnacle and aim it at the alien plant that's in the center of the wall that's over the ledge on the other side of the pit. Lean on the "Primary attack" key until the barnacle pulls you over to the plant, then release it to drop down to the ledge. Go through the door and down the hall to reach a small lift.
Get on the lift and use its button to go down, then get the shockroach out and open the door. Quickly zap the two headcrabs you can see without entering the room, then go over to the left side of the doorway while the door is open to get the attention of the third headcrab. After it leaps and misses you, quickly zap it to death.
You can now enter the room and kill all of the barnacles with the shockroach. Do NOT try to be all "ironic" and kill them with your barnacle weapon, since that will just get you badly injured. Go through the door at the other end of the room, then down the hall to another little lift. Press its button to ride it up, then quicksave.
Past the door is a room with a shocktrooper and two pit drones. Both drones will probably see you as soon as you open the door, so have the SAW machine gun out to quickly shoot them down with. After that, use the spore launcher to blast the shocktrooper. Wait for its shockroach to die, then enter the room.
Look for a first aid station on the wall and a displacer ammo pack on the floor, then go down the hall and through some doors to reach an elevator. Right after using the elevator's button to get it going, scrunch yourself into the corner that's to the left of its doors. After the elevator stops and the doors open, slowly crouch-strafe to the right while firing shockroach blasts until you get to where you can sneak-shoot the rightmost of the two pit drones ahead.
Keep crouch-strafing right and firing shockroach blasts until you've sneak-shot both pit drones to death. Run up to the left corner next to the doors ahead to get them to open, then turn to where you can sneak-shoot the shocktrooper with the shockroach. When the doors close, wait until they open again, then resume the trooper-zapping.
After the shocktrooper and its shockroach are dead, go through the doors and down the hall to some rubble. Edge around the rubble on its right side to find a first aid station and a control room door. There are no pit drones in this control room, so you can relax and search it for supply crates to bash for armor batteries and displacer ammo packs. (WARNING: Don't use the displacer in this control room, or you'll probably be splatted upon return.)
When you're done, return to the elevator and take it back down, then go back to the room where you killed the other shocktrooper-and-drone team. Go up the stairs and through the door, then turn right and go down the hall to reach an area with a few boxes you can bash to find an armor battery.
Past the next door, go down the hall and around the warning marker to reach biodome 03, which has two unkillable tentacle monsters in it. Zap the nearest one with the shockroach until it recedes into the ground, then run past before it can come back out again. Drop down to the ground in a spot safely away from the tentacles, then use the shockroach to break open all the crates in the area.
Doing so will reveal three more armor batteries. If you need any of them, zap the tentacle nearest them to make it recede before you run for them. The same goes for the assault rifle and AR grenades that are near the dead marine. After you've gotten what you want of that, look around for a means of exit.
Look high up on the walls to find a large, dark hole. That's where you need to go, but first you'll want to drop onto a ledge with another dead marine. Get out the barnacle weapon and then the shockroach so that you can use the "Last used weapon" key to quickly switch between them. Switch to the shockroach and zap the tentacle that's nearest the wall hole until it starts to sink, then switch to the barnacle and target the alien plant that's on the wall just below the big hole.
As soon as you're pulled up over the ledge that's below the plant, drop down onto it and back away from the dead marine. Switch to the shockroach and re-zap the tentacle to sink it again, then run over to the marine and pick up the shotgun and hand grenades that are near him. Back out of the tentacle's range again, and move to where you can see the plant that's inside the wall hole. While staying out of the tentacle's range, use the barnacle on that plant to pull yourself into the hole.
Resupply on pod ammo by using the barnacle to pull yourself up to the alien plant that's just above you every time it grows a new pod. (Note that to get to the plant after latching onto it with the barnacle, you may need to jump.) Enter the torn-open vent shaft and move through it to reach a large room with a dead marine and a military radio on the lower floor. Use the radio, then gather ammo from near it and the marine's body while listening to the message.
Use the switch on the power box that's on the wall to the left of the radio, then climb the ladder to get back onto the upper walkway. Go over to the large fan vent and bash its grating off, then jump-crouch into it. Get out the shockroach, then quicksave. Move along the shaft until you start sliding downward to the Pit Worm's Nest chapter.
PIT WORM'S NEST
Section of4a4: MEET THE PIT WORM AND OPEN THE VALVE
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large underwater area in Xen. You can lean on the "Swim up" key to surface for air just about anywhere, so there's no real danger. Search the floor of the area with night vision on to find a health pack near a dead scientist, an ammo canister under a thing that spits a bit of gore out when you first approach it, and two armor batteries next to a dead HEV woman near the exit portal. As with some previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
As soon as this section finishes loading, fire the shockroach at the grating that you're sliding toward. That'll break the grating and prevent you from hitting it and taking a point of damage, though you may still take damage from landing on a crate. To avoid that, start leaning on the "Move backward" key as soon as you zap the grating (or maybe a bit before).
NOTES: If you try to zap the grating before this section loads, it'll be unbreakable. Also, if you start leaning on the "Move backward" key before this section loads, you'll probably get hopelessly stuck right after it loads. If something goes wrong, quickrestore and try again until you make it undamaged.
Move forward until you're next to the ledge that's in front of the door with red lights above it. Wait for the door to open, then either jump-zap the bullsquid in the room past the door with the shockroach, or move back to where you can sneak-shoot it by firing shockroach blasts so that they pass just over the bottom of the doorway.
After it's dead, bash all the wooden crates in the area to find health packs and armor batteries, then jump through the doorway. Bash the crate in the squid's room to find another health pack, then use the red switch to the right of the "01" door to open it. Go around the green toxic pool and up the long red ladder to reach an area with several dead marines and their dropped weapons.
In the next room, go up to the "01" door and crouch-walk through it. Stay crouched as you walk over to the control console, then quicksave. Turn right and run for the edge of the floor. Drop down to the walkway that's a ways down, then run for the doorway. As soon as you're past it, strafe right into a corner. If you do it right, the pit worm won't have a chance to hurt you, and the pit drones that are down the hall to the right won't have seen you yet. (But have the shotgun or SAW machine gun ready in case they do see you and run into view.)
Get out the shotgun and spore launcher so you can quickly switch between them, then select the spore launcher. After quicksaving, turn right and strafe left so that you're facing the pit drones at the end of the hall, then fire off a couple of pods. Strafe back into your corner, crouching so you can fit under the little blue light fixture, and switch to the shotgun. Be ready to double-barrel any pit drones that run up to you.
After they're dead, get the shockroach out and go down to their end of the hall. Zap the pit drone that's near the bottom of the broken-up stairs, strafing to dodge its tooth darts, then wait to see if the second pit drone will walk over to its remains, making it easy to shoot. If not, move along the left ledge to where you can zap-shoot the second drone.
Drop down to the floor through the stair break, then bash open the crates to find a health pack and an armor battery. Get out the spore launcher and make sure it's reloaded, then run over the green alien plant to pick up a pod. Keep getting pods from it until your spore pod ammo is at max, then break the nearby grating and crouch-jump into the vent shaft.
After you break out of the shaft's other end, turn left and use the red lever that's next to the door to open it. This allows you to move between the waste-flushing control room and the broken-stair area without having to use the vent shaft. The waste-flushing control doesn't work yet, so you'll have to go about reactivating two separate support systems. (This is *just* like the Blast Pit chapter in Half-Life. This game is such a copy-cat!)
Turn right from the control panel and go through the "03" door. Carefully crouch-walk up to the next doorway so you can sneak-shoot the pit drone that's past it with the pistol. Go in and get the ammo and health pack from near the dead marine, then climb the ladder. At the top, use the shockroach to zap the pit drone that's in the doorway ahead and to the right.
After it's dead, wait to see if the second pit drone will come over to where you can zap it, too. If not, get off the ladder and crouch-walk over to where you can sneak-shoot it with the pistol. Check near the dead marine for SAW machine gun ammo and a health pack. Crouch-walk through the pit drone doorway and on until you get near another doorway, then quicksave.
Run through the doorway and turn right to find a lever on a big panel that you need to use. Use it quickly, then run backwards and through the doorway for cover. If you get injured by the pit worm, quickrestore and try again until you can make it uninjured. If you keep getting whacked, stand in the doorway until the pit worm starts using its "laser vision." Dodge a blast, then run for the lever before the worm can muster another blast. After you manage to use the lever and get away unhurt, quicksave again.
Stand to where the pit worm can't zap you with its laser vision, and you can see the green alien plants that are on the wall on the other side of the pit worm's room. Use the barnacle to latch onto one of those plants, and quickly jump the nearby walkway's railing when you reach it. If you don't make it to the little platform under the plants uninjured, quickrestore and try again.
This can be a very tough thing to do without injury. Try moving forward to where the pit worm will see you through the doorway and start firing its laser vision, then immediately back up and start using the barnacle to cross. Also, you could try going back down the ladder (after very slowly crouch-walking onto its top to get hold of it), then going through the waste-flushing control room's "02" door. Make sure the pit worm sees you on the walkway past that door, then recross the control room and crouch-walk all the way back up to where you can barnacle across to the little platform.
Yet another thing you could try is returning to the waste-flushing control room and going through the door that leads to the broken-stair area. Run up the left side of the bottom part of the stairs and jump to the top part. This is a tough jump to make. If you miss, you'll have to jump-crouch onto the bottom stair part and try again. Once you make it, crouch-walk down the corridor and over to the doorway you ran in through earlier. You can barnacle up to the alien plants from there, and may have a better chance of making it uninjured.
Stay crouched in the platform's back corner to avoid getting hit by the pit worm. Turn to the wheel and use it, then crouch-walk over to where you can drop down onto the walkway below. As soon as you land on it, uncrouch and run along it until you're safe from the pit worm, then quicksave. That's one big pain-in-the-neck maneuver out of the way. Return to the waste-flushing control room via the open door (or vent shaft) in the broken-stair area, then go through the "02" door.
After quicksaving, make the perilous run across the walkway in front of the pit worm. If you can't make it without injury after several attempts, try going back through the "03" door and all the way back up to the doorway near the lever. Get the pit worm's attention up there, then crouch-walk all the way back through the "02" door without letting the worm see you through the control room's windows. Keep trying until you make it across undamaged, then use the red switch to get to section of4a5.
Section of4a5: GET THE GEARBOX GOING
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a fatal-fall area that's like the one in section of3a5 in a previous chapter. Do not do!
Go through the open door and turn left, then turn night vision on so you can see to use the shockroach to sneak-zap the pit drone that's just past the left side of the next doorway. Get the dead fatguard's dropped .357 pistol from the left part of the metal platform, then look for a way down to the floor below. There's a ladder leading from the platform to the floor, but it's kind of hard to get onto without falling.
You could slowly crouch-walk onto the ladder's top to get hold of it, but it's easier to drop onto the wide ledge that's on the right side of the room, then jump to the ladder and climb down from there. Get the shotgun shells from next to the dead marine, then crouch-walk through the "02" door and move carefully to where you can sneak-zap the pit drone that's to the left. Get the ammo from near the other dead marine, then go through a doorway to reach a large room full of crates.
Drop into the room and turn right to find two bashable wooden crates. The small one has a health pack in it, and the big broken-open one contains a displacer ammo pack. Jump-crouch onto the silver metal box that's next to some larger crates, then jump-crouch onto the shorter of those crates. Run across it to drop down past the main crate blockage so you can exit the room through its other doorway (which you'll have to jump through).
In the next hall, zap all three barnacles to death, then jump over the toxic spill at its narrowest point. Enter the small lift past the spill and use its button panel to go up to a higher walkway. Crouch-walk forward to the next corner, then turn left and fire the shockroach to see if you can hit the pit drone that's ahead. You should be able to before you come within sight of it.
After the first drone is down, wait a few seconds in case the second one moves around, then sneak-zap it. Go past them to find a big red button mounted next to a large window overlooking the crate-clogged room. Press the button to start the room's trash-masher walls going, then return to the little lift and take it down.
Jump over the toxic spill again and turn right to reach the crate room's door. If it's closed, wait until it opens, then go through it to find yourself in a narrow "alley" between the two trash-mashin' walls. There'll be an armor battery and a box of shotgun shells there in addition to the health pack and displacer ammo box you could have gotten before.
Break the large floor grating that's under the shotgun shell box and drop down into the water. Climb the short ladder and smash the glass, then get out the shockroach and crouch-walk over to the corner to where you can sneak-zap the bullsquid that's down the walkway. (This is another case where you can zap the target without actually seeing any part of it.) Go down to the dead squid and turn right to find a short walkway that leads to an emergency override panel.
Use the panel's red push-button, then quickly run back to the spot where you fell into the water. Lean on the "Swim up" key as the water rises to keep your head above it. After it stops rising, you can go up through the floor hole you fell through, then jump through the door that leads back the way you originally came. Climb up the ladder to the metal platform you killed a pit drone on, then return to the room with the door switch. After quicksaving, use the switch to get back to section of4a4.
Section of4a4 (again): KILL THE WORM AND CROSS THE BRIDGE
As soon as the door leading to the pit worm's room opens, run through it and along the walkway. The worm may take a few seconds to realize you're there, and you'll have a good chance of making it uninjured. If you get whacked, you may want to quickrestore and try again.
Return to the waste-flushing control room and use its control panel's central button to flush toxic waste into the pit worm's room and kill it at last. (Be sure to stay away from the windows until after the worm's dead so it can't laser-vision you.)
Go through the control room's "03" door and back around to the walkway next to the steam vent lever panel. Crouch-jump onto the walkway's railing, then crouch-drop onto the lower walkway below. Use night vision to help you find the ladder that leads up to the floor with the bridge control panel on it, then use the panel's button to extend the bridge that the pit worm was blocking.
If your health and/or armor are below 100, turn around from the bridge control panel and go through the door. Return to the top of the long ladder you climbed earlier, and climb back down it. (Remember to very slowly crouch-walk onto the ladder's top to get hold of it.) Return to the room where you fell out of the vent shaft earlier and pick up any leftover armor batteries and health packs.
Go back to the bridge control panel and crouch-drop down to the bridge. Cross it and use the red lever to open the door, then go down the next hallway until the Foxtrot Uniform chapter loads.
Section of5a1: BLACK OPS BATTLES AND RIGGED EXPLOSIVE AREA
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large Xen cave that's identical to the one in section of4a1 in a previous chapter, except that there's no scientist and the exit portal is in a different spot. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Push up against the door to open it, then quickly shock-zap the bullsquid that you can just barely see at the other end of the long room while dodging its toxic spit. After it's dead, go into the room and along the walkway until you come to a broken spot. Jump across it, then move on to reach a doorway.
There's another bullsquid a bit to the right of the doorway, so get out the spore launcher and quicksave. Fire off a couple of bouncy altfire pods so that they bounce over to the bullsquid, and quickrestore if any bounce back and hit you. After the squid is dead, go through the doorway and turn left to find several crates to bash for health and armor. Jump up against the nearest green plant to collect a pod, then get out your barnacle weapon and look up.
There are three other green plants visible nearby, and you'll want to use the barnacle weapon on one of the two highest ones in order to get onto the small platform that's under them. Look up to the ceiling from that platform to find a large plant growth that you can barnacle over to in order to land on a higher platform. (Strafe right as you drop down from the plant to make sure you land on the platform.)
Get out your spore launcher and check your pod supply. If it's not full, use the barnacle to pull yourself up to the two plants on the ceiling above your platform until you have all the pods you can carry. (Note that you may have to jump after attaching the barnacle to a plant in order to get its pod.)
Jump the small gap that separates your platform from another one, then jump over the railing to get onto the walkway. Climb about halfway up the ladder, then quicksave before climbing out onto the street. Run toward the open red storage container, but don't enter it. Instead, run past its right side and all the way to the corner that's next to another red storage container.
The black ops guy at the mounted gun farther down will see you and shoot at you, but he should miss, and the black ops guys that just arrived in the truck won't realize you're there. Carefully crouch-strafe to the left until you can stand up and see an explosive crate in the distance. Shoot it with the pistol until it explodes, killing the guy manning the mounted gun.
Crouch-strafe to the left some more to see where the black ops guys from the truck are. They should all be behind the truck to where they can't see you, and you can only see their legs at most. If this isn't the case, and one of them spots you, quickly run into the open red storage container and use the SAW machine gun to shoot down black ops guys as they appear.
If they are all behind the truck, get out the spore launcher and take careful aim at the one whose legs you can see between the truck's front and back sets of wheels. If you crouch and fire a pod at the top of those legs, you should score an instant kill. (Quicksave first in case you need to try again.) Crouch-walk over next to the truck's right front wheels, then quicksave again.
Look just to the right of the truck's back right wheels to see another black ops guy. It's kind of hard, but you can fire a pod so that it'll splattify him in one hit. When you do, the last black ops guy may or may not run past the back of the truck and see you. If he does, quickly turn and kill him with a pod. If that damages you, quickrestore and try again. If he doesn't run over, kill him by firing pods just over (or just to the right of) the truck's back left wheels.
Reload the spore launcher, then go over to the large leaning red storage container that's across the street from the mounted gun. Enter the container through its open end, then crouch-walk up near the next container's big hole in the wall. Turn to face the hole, then strafe slowly to the right until you can see a black ops guy up in a little lookout tower a ways ahead. Fire a pod at him to kill him.
Stand up and strafe over to the big hole, then spore-blast the two black ops guys who are down on the ground as quickly as you can. (You may want to first toss a few snarks through the hole to distract them while you spore-blast them.) Reload the spore launcher, then turn and go back the way you came. Carefully crouch-walk onto and climb back down the manhole ladder, then jump over to the platform with the two alien plants above it. Use the barnacle to get up to those plants and resupply on pods.
After you're full up on pods again, jump across and climb back up to the street. Go into the nearby open red storage container to find two C4 satchel bombs and a SAW machine gun. Pick up the black ops guys' dropped guns if you need bullets, and look next to the mounted gun for a rocket, a tripmine, and a C4 satchel bomb. You can also get two health packs by bashing the big crates that are just past the storage container blockade.
Get back into the storage container with the big hole in the wall, then bash the crates in one corner to find some AR grenades. Drop down to the ground past the big container hole, then turn around and look back at it. It is possible to get back up to it by jump-crouching onto the lowest gray crate, then jump-crouching onto the highest gray crate, then jumping onto the lower red storage container's corner, then carefully crouch-walking along the narrow ledge that leads back to the hole. (This can be useful later on if you want to go back for leftover supplies.)
Bash all the crates near the black ops lookout tower to find a rocket, then go down to where you can crouch-walk under the right wall through a small hole to get inside a building. While the two marines in there gripe about the black ops snipers, look around on the shelves for supplies. There's also an armor battery on a green crate that you can jump to from on top of the shortest green crate.
Go over to the exit doorway that's past the marines, then get out the .357 and quicksave. Crouch-walk very slowly through the doorway while looking up at the lookout tower that's to the right. When you can see the right arm of the black ops guy in the tower, carefully shoot it until he's dead. Go through the doorway with the shockroach out, then strafe right until you can see the next black ops lookout tower down the line. Its resident will see you, but probably won't be able to shoot you at that distance. Whether he can or not, quickly zap-kill him with the shockroach.
NOTE: This whole outdoor area is rigged with lots of explosives, just like one building was in Half-Life's Surface Tension chapter (copy-cat again!). There's no way to detonate all those explosives without dying, even if you toss a C4 satchel bomb near some of them and go all the way back down into the manhole before detonating it. The game is rigged to fade you out and load up the most recent save every time the explosions start. What a cheat!
Return to the doorway and go left from it to get to where you can see a black ops sniper (complete with sniper rifle) behind some netting in a large high-up window a ways ahead. Kill him with the shockroach, then run forward to some red storage containers. Turn right and go around the red containers until you come near the doorway that leads into the sniper's building.
There's a black ops guy standing next to the doorway, so strafe to where you can only partly see him, then sneak-shoot him with the spore launcher. If the first pod doesn't kill him, quickly fire another one or two before he can start shooting at you. Go through the doorway past him and climb a ladder to get to the sniper's nest.
His sniper rifle should be there, but it may have fallen down to the ground outside. If so, grab the box of sniper ammo, then go back outside and around to where you're under the sniper's net-covered window. Once you have the rifle and the ammo, go back to the two red containers that you turned right from earlier, and this time turn left. You'll be facing a short alley that has two tripmines and two large "DANGER"-marked metal explosive packs in it.
To get over the tripmines, jump-crouch onto the nearest explosive pack's "DANGER" sign, then jump-crouch onto the top of the pack, then jump over the laser beams. Or if you're playing a game version earlier than 18.104.22.168, you can very carefully crouch-walk up to the lower tripmine, then crouch-jump onto it and crouch-walk past it. (Using this alley instead of going around the way you're "supposed" to keeps several black ops guys from appearing. Remember that if you ever want to go back to previous areas to get supplies. Always use this alley!)
Go through the nearby doorway, then find the other doorway in the back that leads to a storage room. Get the displacer ammo packs from the shelf and the SAW machine gun ammo from the green crate, then go back outside. At the end of the alley, turn left and move slowly forward to an open area with very short sandbag walls, a large metal crate stack straight ahead, and some explosive crates to the left.
Get out the sniper rifle and look over to the right for some wooden crates past a corner. Move carefully to where you can see the right arm of the black ops guy who's behind those crates, then use the rifle's zoom mode to snipe him down with one quick shot. There are two more black ops guys hiding behind the large metal crate stack that's straight ahead, and they're set to roll out from behind it when you get close.
If you run straight for the middle of their crate stack and stop there, they won't see you when they roll out. While facing the crates, turn left and crouch-walk slowly along until you can sneak-shoot one black ops guy with the sniper rifle. Immediately turn around and watch for the other black ops guy to slowly walk into view, at which time you should snipe him down, too.
The area is now enemy-free, so grab the sniper rifle that's on the ground nearby, then bash all the non-explosive crates to get two armor batteries. Find the huge partly open doors in the back right corner of the area and go through them. Go past the big red container stack on its left side to reach section of5a2.
Section of5a2: VOLTIGORE SEWERS AND INFINITE PIT DRONE AREA
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large Xen cave that's identical to the one in section of3a4 in a previous chapter, except that there aren't any armor batteries. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Get out the SAW machine gun and quicksave, then move forward until you start hearing the sounds of a battle. Quickly run behind the crate stack on the right, and stand in the corner next to the big red container stack. You probably won't need to use the machine gun against any black ops guys who run into your room briefly to reload, but be ready to just in case.
After everything goes quiet, quicksave before cautiously moving into the room where the battle took place. The most likely scenario is that there's only one shocktrooper left, and it's next to or behind a crate stack on the upper floor to the left. However, it is possible that the black ops won, or that there's more than one shocktrooper left. Sneak-shoot the survivors with the spore launcher, shockroach, or whatever works best for the situation.
After you're sure the place is free of hostiles, jump into the back of the big truck at the loading dock and bash all the crates for health packs and ammo. Don't miss the SAW machine gun ammo and sniper rifle ammo in the very back. Return to the "front" of the back of the truck and jump across to the concrete ledge on the left. From there, jump across the wide gap to the concrete ledge against the wall, then turn right and jump to the crate that's on the floor next to the stack of crates. Jump from there to the little ledge in front of you and bash the boxes to find a health pack and a C4 satchel bomb.
Drop back down to the floor, then go up the ramp that leads to the upper walkway. Look around with night vision on until you find the ladder that goes down into a hole, then think about whether or not you want to go back to previous areas for supplies. You could make it all the way back to the start of the pit worm's area if you wanted to.
When you're ready, make a regular save, then climb down the ladder and start walking down the dark sewer tunnel with night vision on. Soon after you pass a skeleton with an assault rifle near it, some clumsy idiot up above will detonate the super-explosive area, and the top of the ladder you just climbed down will be blocked by rubble.
Walk slowly down the sewer tunnel until you come to a T-intersection. Quicksave there, since there are several voltigores in these tunnels, including one down the left branch of the T-intersection that'll see you as soon as you step into the intersection. You could try to quickly kill it with the RPG, spore launcher, etc., but a better way is to let it see you and then run back to the base of the ladder as fast as you can.
When you reach the ladder, turn to face the way you came and wait to see if the voltigore will run into view. If it does, quickly run up the ladder as far as you can. If it doesn't, go slowly back along the tunnel to see if it got stuck somewhere nearby. If it didn't, go to where it'll see you and start chasing you again, then run back to the base of the ladder and repeat the process of checking its progress.
If the voltigore gets stuck in the tunnel, go to where you can shoot it to death with the shockroach without it being able to fire at you. If it followed you all the way to the ladder area, climb back down the ladder slowly until you can zap the voltigore with the shockroach. (You don't necessarily have to see any part of the beast to do that.) If you're able to kill the voltigore without getting zapped at all, quicksave.
WARNING: If you're playing version 22.214.171.124 or 126.96.36.199 of the game, the shockroach has a serious glitch that is very likely to start happening in this area. If you see a sizzly zap effect around it even when you're not firing it, you'd better switch to another weapon for awhile. (The SAW machine gun works extremely well against voltigores.) Also, whenever you want to save, make a quicksave and then see if quickrestoring will crash the game. If so, you'll have to restore an earlier quicksave or autosave (or the regular save you made just before entering the sewers) and play on from there, perhaps without using the shockroach at all.
Go back to the start of the long tunnel section that has the T-intersection in it and fire the shockroach down the tunnel a few times to see if another voltigore saw you and decided to follow you. If so, quickly use the above process to get it stuck somewhere and zap it to death. Otherwise, go find another one to use the process on.
NOTE: Another way to get a voltigore stuck somewhere so that you can safely stand and zap it to death is to set a tripmine. Voltigores will sometimes cross a tripmine's laser and detonate it, but not usually. At the beginning of the left branch in the T-intersection is a good spot to set a tripmine. In fact, you may want to do that from the start to see how many voltigores you can snag and zap there.
As much as I despise scuzzy-looking plain-text maps, I'm going to provide one below that shows both of the sewer areas that are connected by the pit drone area (which will be described soon).
XX ---> pit ---> X X
XX drone X V X
XXXXXXX XXXXXXXXXXXXX area XXXXXX X XXXXXXXXXXXXXX
XXXXXXX XX V XXXXX X XX XX XX
XXXXXXX XX XXXXX X XX XX V X X
XXXXXXX XX X X XX XX X X
X b XX X X X XX XX XXXXXXX X
X b V XX X X X V XXXXXXX X
X b XX X X XXXXXXXXXXXXXXX X
X b XXXXXXXX V X X X v X X
X b V V X X = tunnel wall X X v X
X b XX X X V = voltigore X v XXX
X b XXXXXX X v = baby voltigore X X
X b XX X X L = ladder XXX XXXXXXX
X b XX LX X b = big pipe X X
X b XX X X X X
X b V XX X XXXXXX X
XXXXXXXXXXXXXXXXXXXX to exit <--- X
Using the map, you can see where all the voltigores start out, and how to navigate the sewer tunnels. Use the above tips to zap-kill all five voltigores that you encounter before you reach the big pipe, then go over to the pipe and crouch-walk up to where you can sneak-shoot the last voltigore in this half of the sewers with the shockroach.
Watch for the voltigore trying to come after you. If it does, it may get stuck next to the pipe, or it might actually glitch its way past the pipe and come after you, in which case you'll need to lead it to a point where it'll get stuck (like near the ladder) so you can safely zap it to death.
After it's dead, go past its starting point and into the large tunnel that leads to the pit drone area. There will be one pit drone on the area's far walkway that'll see you as you enter the tunnel, so quickly shoot it down with the sniper rifle in zoom mode. Move along the tunnel until you enter the water and come to a ladder on the right.
Get out the .357 and climb the ladder slowly until you're just able to see and shoot the pit drone that's a ways directly ahead of you. There's another drone in the dark area behind it, but it won't come out after you. However, it may start spitting teeth at you. If so, use the sniper rifle in zoom mode to take it down.
After quicksaving, climb up the ladder and start running along the left side of the walkway. That'll cause the pit drones that come out of the dark spawning area to move over to the left side of the walkway to intercept you. When you're about to collide with the first of those pit drones, quickly strafe over to the right side of the walkway. You should then be able to run up to the big lever, use it to close the spawning area's door, and then dive into the nearby water without getting damaged. If you do get hurt, quickrestore and try again.
Swim underwater all the way to the other end of the area, then turn around and hold down the "Jump" key to bob on the surface of the water. The pit drones should be clustered down at the other end of the water, and they shouldn't be able to spit teeth at you. If they can, you'll want to quickly take them out with the sniper rifle, ducking under the water when you need cover. Otherwise, take your time and zap them all with the shockroach. (Just be careful not to fire it while underwater!)
After they're all down, swim through the hole in the nearby bit of fencing, then climb up the ladder again. Quicksave, then go down to where an unbroken walkway bridge crosses over to the other side of the room. As soon as you're across the bridge, turn left and start running along the left side of the walkway. You're going to repeat the process of faking out the pit drones and using a big lever to close their spawning area's door, then jumping into the water and zapping them from there. It works just like before, except you don't want to swim to the other side of the area -- just stay near where you jumped in.
If the trick of faking the drones out by strafing left-to-right in front of them never works for you, then use the SAW machine gun to quickly kill them as you run for their door lever. Don't pause to kill ones that run by you, but only ones that get in front of you. (Or quickly kill the first three that run out, then go for the lever.) Keep trying until you find some way that works for you.
After you close the second pit drone door and finish off the loose drones, swim through the fence hole and climb the ladder again. This time, turn around and go along the narrow bit of concrete above the fence that leads to some crates you can bash for supplies. When you're done there, cross to the other side of the room again and find the big semicircular hole in the wall that leads to the second section of voltigore-infested sewers. (Refer to the right half of the scuzzy text map above.)
What you want to do with the three adult voltigores in this sewer section is get them to follow you back to the pit drone area. They'll get stuck trying to follow you out of the tunnel, making them easy targets. So get one's attention and lead it along until you exit the tunnel, then quickly turn left or right and find a position from which you can safely zap it. After it's dead, check to see if another voltigore is right behind it. If so, zap it. If not, go down the tunnels until you find another one to repeat the process on.
After all three adult voltigores are dealt with, move on to the second part of the tunnels to find three baby voltigores. Aren't they the cutest little things? There's no need to lead them anywhere in particular -- just zap them with the shockroach while backing up to stay out of their melee range. After they're all dead, go through their nesting area and find the tunnel in the back that'll get you to where section of5a3 loads.
Section of5a3: BIG VOLTIGORE AND SHOCKTROOPER COMBATS
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a rocky platform area in Xen that's very similar to the one in section of3a6 in a previous chapter. There will be no higher platforms that you can't reach, the left route has an AR clip and AR grenades along it, the right route has nothing along it, and there won't be a health pack near the exit teleporter, but otherwise it's just the same. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
When you reach the area with a ladder on one wall, climb up it until the marines in the room above notice you. Climb back down and use the two alien plants on the floor to resupply on spore launcher ammo, then go up the ladder and into the marines' room. While they're talking about the situation at the dam, get the sniper rifle and assault rifle off a green crate, then check the shelves in back for a health pack and SAW machine gun ammo.
Go out through the room's doorway, then crouch-walk slowly past two big crates to where you can turn left and see your wrecky building's big front doorway and windows. There's a shocktrooper in the street ahead, but it won't see you if you stay so that the wall piece to the right of the big doorway is between you and it. Look for a fallen-over metal explosive pack behind the trooper, and shoot it with the pistol to blow it up and injure the trooper.
Quicksave again, then sneak-shoot the trooper with the shockroach. When it moves to where it sees you, quickly run back to the marines' room's doorway and hide in the dark corner that's to the right of it and next to a large crate. Jump up and down there to see if you can zap the shocktrooper over the crate. If it runs back there after you, crouch in the corner and hope the SAW-wielding marine near the doorway will kill it and its shockroach for you.
Quicksave after that first shocktrooper is dead (or runs out of view and doesn't return), then go over to the building's big doorway to let a voltigore and a couple more troopers see you. Quickly run back for your dark corner near the marines' doorway before you come under attack.
The voltigore will almost certainly get stuck in the building's doorway, blocking the way for the troopers. If it doesn't get there fast enough to keep troopers from coming in, you might want to quickrestore and try again. In your corner, you can jump up and down to zap the voltigore over the crates. (Or you can just jump up and down and see if the troopers behind it will eventually kill it for you by accidentally hitting it while firing at you.)
After the voltigore blows up, stay in your corner as the remaining shocktroopers come in to attack you. Do them the same way you did the first one. After they stop coming, there should only be one shocktrooper left in the immediate area. It's around the corner to the left of the building's doorway, so either try to sneak-shoot it with something or get your marines over there to deal with it.
After it's dead, go across the street from the building's doorway and through the opening between big storage containers that you shot an explosive pack through earlier. Look in the back left corner to find an open storage container with some hand grenades and three C4 satchel bombs in it.
Look near the two short sandbag walls that the last trooper was near for some SAW and assault rifle ammo, then look around the far end of the netting that's on the ground to find a place where you can crouch-walk between two large chunks of rubble. After crouch-walking to the back, stand up and take a running jump at the lower rubble chunk to get onto it, then run over it and drop down on its other side.
You could then immediately go through the broken security door on the right, but there are two supply areas you'll probably want to visit first. Go down the alley next to the security door until you reach some badly broken-up pavement. Jump your way across it and go around the left side of the damaged red storage container. Go straight to the back wall, then turn right and move forward to find the first supply area, which has a shotgun in a box, some .357 ammo, and a C4 satchel bomb.
Go straight when you leave the first supply area to reach a narrow alley with two fires burning in it. Carefully move around the fires, then on to where you'll find the second supply area on the left between several large blue storage containers. It has a shotgun in a box, a C4 satchel bomb, and a health pack. Move on past it and through an open blue storage container to return to the area you started in.
A bunch of shocktroopers have been spawning in the areas behind you as you went through them, so if you want to get the three marines' guns, lead them to the open blue storage container you just came through so they'll fight the nearest group of shocktroopers and get killed. The problem with this is that you'll have to finish off any leftover troopers yourself. You may want to just skip that.
Go back over the rubble past the netting to return to the broken security door, and this time go through it. Turn right past it and go forward until section of5a4 loads.
Section of5a4: GARGANTUA ON THE DAM
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large underwater area that's identical to the one in section of4a4 in a previous chapter except that there are two exit portals, one at each end of the area. As with previous sections, the exit portals will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
You'll soon come to a room with two boxes of SAW machine gun ammo on a green crate, plus first aid and HEV stations on a wall. Go through the nearby broken security door to return to the dam area that you first visited as Gordon Freeman near the beginning of Half-Life's Surface Tension chapter.
There's now a gargantua tied down at the center of the dam, with explosives set near it. How in the world the marines ever managed to tie down a gargantua, I'll never know. The deal here is that the two surviving marines on the other side of the dam are too "dam" stupid to use the plunger that's near them to blow up the gargantua, and are instead shooting at it uselessly. You'll have to destroy the big beast yourself, and there are three good ways to do it.
WAY #1: You can't cross the dam directly with that gargantua in the way, so drop into the water on either side of the dam and swim over to where you're next to its other side. Get out the barnacle weapon and use it on an alien plant to pull yourself up onto the ground next to the dam, then quickly switch to the spore launcher and help the marines kill the two shocktroopers that teleport in. As soon as they're finished off, use the plunger to set off the charges and destroy the gargantua.
WAY #2: Cross the water and pull yourself up to get the shocktroopers to teleport in, then drop back into the water. Wait and watch as the troopers kill the marines and then start attacking the gargantua. Why would they do a thing like that, I wonder? If you wait long enough, they'll eventually blow the gargantua up. That's hilarious, but you'll then have to kill the troopers yourself. (The easiest way is to do so from the water with the sniper rifle or spore launcher.)
WAY #3: Instead of crossing the dam, stand in the broken security door's hole and shoot regular-fire pods at the gargantua with the spore launcher. It'll probably break free of its restraints before you can kill it, but that's okay, since it can't fit through the security door's hole. Just back up a ways and continue to spore-blast it while dodging its sonic stomp attacks. (Note that you could instead kill it with the shockroach, but that would take quite awhile.) After it blows up, get the two marines to follow you, then run for the corner to the right of the ramp that's past the dam, firing off one quick spore launcher pod at the first shocktrooper that teleports in. Crouch down in the corner while your marines fight the troopers, then finish the job yourself if necessary.
If you used the spore launcher for anything, the first thing you should do is use your barnacle weapon to pull yourself up to the alien plants on the cliff walls near the dam to refill your pod supply. Be careful not to lose any health from falling after letting go of a plant. You might want to quicksave after every five pods gathered just in case.
If you haven't used the plunger to blow up the dam charges yet, it'll be easy to recross the dam and heal up at the first aid and HEV wall stations past the broken security door. Otherwise, crouch-jump carefully onto the narrow ledge to the left of the big dam hole, then do a running jump-crouch across to the other side. If you fall into the hole, walk/jump out of it and try again.
After you're healed up, go use the plunger if you haven't already, then drop into the dam hole and enter the broken-open pipe. Walk along it until you fall down into some fast-running water, then go with the flow until the "The Package" chapter begins.
Section of6a1: BLACK OPS MOUNTED GUN AREA
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large Xen cave that's identical to the one in the of4a1 section in a previous chapter except that the exit portal has moved a bit. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Flow along with the water until you come to an unbreakable grate blocking your way. Turn around and go against the flow to where you can move into a side tunnel, then go out through its broken grate to a pool of water. Jump onto the low end of the barrel that's floating in the pool, then use it to jump onto a rocky ledge. Follow the rocky ledges up to a concrete ledge, then move along it to find a dead marine with a shotgun and a box of shells next to him. (NOTE: I found it impossible for some unknown reason to get up onto the barrel when I played with patch version 188.8.131.52 or later installed.)
Drop back into the water, then swim to its other side and run up to where two marines are standing. Don't stop to listen to them, but run on by them to reach a spot where you can shockroach-zap a black ops guy who's standing in some water. As soon as he's down, get out the sniper rifle and very slowly crouch-walk over to where you can see the mounted gun that's on a small hill a ways to the left.
Use zoom mode to snipe down the mounted gun's operator before he can shoot at you, then switch back to the shockroach and get the two marines to follow you. Run into the water and past the crashed chopper on its right side, then keep running until you get onto a small patch of land with a cactus on it. Turn and watch for a black ops guy to stop in a spot just across the water, and start zapping him the instant he does. Zap down the second black ops guy as fast as you can, then have your marines stay put in a spot near the cactus.
Cross the water and run up to the mounted gun, then use it and immediately start firing continuously at the ground directly ahead of it and across the water. You should be able to kill the three black ops guys who appear down there quickly enough that they won't have a chance to shoot back. Get the two health packs from near the mounted gun if you need them, then go get your marines to follow you again. Follow the water along until you reach section of6a2.
Section of6a2: BLACK OPS MORTAR LAUNCHER AREA
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a rocky platform area in Xen that's nearly identical to the one in section of3a6 in the previous chapter. There will be no higher platforms that you can't reach, the left route has .357 ammo and hand grenades along it, and there won't be a health pack near the exit teleporter, but otherwise it's just the same. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Soon after this section loads, talk to your marines to get them to stay put so they won't get killed uselessly. Run into the large open area where a black ops guy is manning a mortar launcher. Run toward the mortar until you pass between a tank and a crate stack, then turn right and run for the leftmost slanty bit of concrete that's near the "ORDINANCE STORAGE FACILITY" sign on the back wall.
Jump onto the slanty concrete and run up it, then turn left and go along the concrete ledges until you're standing next to the mortar platform. Get out your barnacle weapon, then back up to where you can use it on the black ops guy to pull yourself up there and chew him up. What a shortcut!
Get out your shockroach and crouch-walk around the mortar control panel to a spot behind the mortar launcher. Two vortigaunts will have teleported in on the ground near the blasted building, but they probably won't stay there long enough for you to mortar-shell them. They'll soon teleport up onto your platform, and you'll want to be under cover next to the mortar launcher so you can shockroach-zap them without them being able to zap you in return. If they never teleport up, either zap them or mortar-blast them (see next paragraph) on the ground.
Go over to the mortar launcher's control panel. The left button turns the launcher left and right, the right button raises and lowers the altitude of its shots, and the central red button fires it. If you're pressing a movement button and it's not moving in the direction you want it to, release the button and press it again while facing it from a slightly different angle.
Turn the launcher all the way to its leftmost facing, then fire it. You want it to tear out a chunk in the left part of the fence wall that blocks access to the area near the rightmost "ORDINANCE STORAGE FACILITY" sign. If it didn't, adjust its altitude and try again. Once there's a big triangular-shaped hole in the fence wall, you could drop to the nearby concrete ledge and then to the ground, jump through the fence hole, and go through a door that leads to section of6a3. However, there's lots more to be done in this section, and I encourage you to stick around and do it all before moving on.
Go through the door on your ledge and over to the top of some stairs, then get out the .357 and quicksave. Crouch-walk down the left side of the stairs until you can sneak-shoot a black ops guy who's on the floor between stair sets. He'll run away, so cross the floor and crouch-walk down the right side of the second set of stairs until you can sneak-shoot a black ops guy through the doorway on the left.
He probably won't move, so keep shooting him until he goes down. Crouch-walk to the bottom of the stairs, then up to the doorway to where you can sneak-shoot the guy who's at the end of the walkway past the doorway. He'll move forward and see you, so quickly finish him off, then shoot down the next guy who runs into view. After that, all you have to do to clear the area is sneak-shoot the guy who's over on the right past the doorway, near the top of some stairs.
Go down the walkway past the doorway to find a room full of crates you can bash for supplies. There's no reason to go down any more stairs, so go back up to the top and out onto the mortar platform. Drop down to the nearby ledge, and then to the ground. Go over to the large crates near the tank and bash them open (if the black ops guy didn't mortar-blast them earlier while trying to hit you) to find an RPG and a spare rocket.
Use the shockroach to blow up the tank's turret and the top of the water tower (or maybe it's a gas storage tower) for fun, then find the small door that's to the left of the hole you blasted in the fence wall. Past that door, crouch-walk along until you turn a corner and can sneak-shoot a black ops guy over on the right with the .357. He may charge you, so quickly take him down.
Bash open the crates in the room for health and armor, then go downstairs and use the radio. Get the SAW machine gun out and go outside, ready to shoot down two black ops guys who are near the blasted building. Since the SAW isn't too great at long-distance shooting, you might want to peek outside to get the black ops guys' attention, then go back inside and wait a few seconds. Push the door open again and shoot them down at close range.
Go outside and past the tank to find that one of the large metal bunker doors is now open. Drop through the open door and go down some steps to find a room with a health pack and a SAW machine gun on the floor, plus a SAW ammo box on a small green crate. To get back outside, go up to the open bunker door and jump-crouch onto the ground.
And now it's finally time to utilize the two marines you brought into this section with you. Go back to where you left them and get them to follow you again, then go over to the blasted building and leave one marine standing near the spot where a large chunk of rubble forms a ramp leading down to the building's floor. Leave the other marine standing on the ground near the opposite side of the building, then drop down to the building's floor.
Get out the SAW machine gun and quicksave, then go over to the dead marine who has supplies near him. That'll cause three shocktroopers to teleport in on the ground above, so start helping your marines shoot them as soon as they appear. If you get too badly damaged for the nearby health packs and armor batteries to fully restore you, you might want to quickrestore and try again, using more cover or setting C4 satchel bombs where you know the troopers will teleport in. (If you use the C4 trick, relocate your marines so they won't be hurt when you detonate the satchels.)
Gather the building's supplies, then return to the open bunker for SAW ammo if you need more (and if there's some left there). If you want to return to the supply area in the building adjacent to the mortar platform, jump onto the broken radio's crate in the bunker, then jump to the crate next to it, then jump to the crates next to the big pipes. Drop down into the area between the pipes and run (then crouch-walk) your way through them to where you can exit the pipe area. Go up some stairs to reach the floor with the supply room, then go back up to the mortar platform and drop down to the ground from there.
Now you're finally done with the area and can go jump over the hole you blasted in the fence wall. Go through the small door past the hole, then down the wrecky hallway until section of6a3 loads.
Section of6a3: BLACK OPS CHOPPER AND PARKING GARAGE
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large underwater area that's identical to the one in section of4a4 in a previous chapter except that there are two exit portals, one at each end of the area. As with previous sections, the exit portals will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Quicksave as soon as this section loads, then run forward and turn right to find a large hole in the wall that leads outside. Run up to the hole, then quickly back up and strafe left to avoid enemy fire. If you do it right, you'll have "activated" a chopper that will fly back and forth overhead, shooting the voltigore and shocktroopers out there for you. Hide about halfway down the wrecky hall, but don't go so far down it that the previous section reloads.
Have the SAW machine gun out in case any shocktroopers appear in front of you, though hopefully none will. Wait and listen as the chopper flies by and fires on the aliens. After you hear it make several fly-bys without firing at all, quicksave, then go slowly over to the wall hole to see if there are any aliens left. If so, either quickrestore and wait for the chopper to get them, or kill them yourself to speed things up.
After the yard is clear, get out the RPG and go stand in the wall hole and look up. Fire a rocket at the chopper as it's flying left-to-right in front of you, and you should be able to easily hit it without coming under fire. If the first rocket doesn't destroy it, repeat the rocketing process until it goes down in flames.
Go out through the wall hole and turn right, then crouch-walk up to the doorway in the wall ahead. There's a shocktrooper hiding a ways to the left of the doorway, so get to where you can sneak-shoot it with the shockroach while watching for it to move around. If it sees you, you can retreat for cover and not have to worry about it coming out after you.
Look around inside the building with night vision on to find a couple of health packs and a doorway that leads to some wrecky stairs. Go up the stairs to reach a higher floor. Go over to the small wall hole that leads to a new area, then quicksave. After you drop down, you won't be able to get back up (unless you use several tripmines as stepping stones, which you can only do in game versions earlier than 184.108.40.206), so think about whether you want to go back to previous areas for supplies.
Get out the SAW machine gun and drop through the hole onto a machine, then drop to the ground. Look to the right to see if there's a voltigore over there. If there is, quickly kill it with the machine gun while dodging its electric blasts. If not, the chopper must have gotten it.
Look inside an overturned truck for two armor batteries and some sniper ammo, then move past it to find a ladder on a wall. Crouch-walk into the turned-over dumpster to the left of the ladder to find two displacer ammo packs, then climb the ladder.
You can now use a tripmine shortcut if your game version is less than 220.127.116.11, though I advise against it. What you'd do is turn left after you climb the ladder and go over next to the higher roof. Set a tripmine so that you could jump-crouch onto it, then jump-crouch onto the higher roof's slanty part, then crouch-walk up onto the roof. You'd then be on the roof past the electrified line and could continue from there.
The longer and better way starts by getting onto the higher roof that's to the right of the ladder. You do that by jumping onto the short, round black thing, then jumping onto the square vent thing, then jumping to the roof. Go to the other side of the roof and crouch-drop down off of its left side. Crouch-walk under the left side of the large jammed-open door, then go through the smaller door to reach a room where you can resupply on RPG rockets.
Find the power box near the rockets and use its switch to de-electrify a wire that you're going to be tightrope-walking across in a minute. Go back under the large jammed-open door and climb the ladder to get back onto the roof. Go over to the place on the left edge of the roof where the newly de-electrified wire starts, then carefully crouch-walk your way across it. At the other end, crouch- hop onto the roof. Look for a health pack nearby, then run along the roof to the back section.
Jump onto the big vent structure back there using one of the curvy things, then drop through the open grating and on down to another set of gratings. Don't drop through the next open grating right away, though. Get out the shockroach and crouch-walk onto the grating that's to the right of the open one, then look down through the open one to see a shocktrooper standing near the top of a street that slopes downward.
It can't shoot back at you, so take your time in zapping it to death. After it's down, move over to the top of the grating that's hanging open and edge very slowly to where you can sneak-shoot a nearby pit drone with the pistol. It's hard to get into the right position, so you may want to quicksave before you try.
Drop down to the pavement after the pit drone is dead, then enter the nearby security booth to find two health packs and some SAW machine gun ammo. There's another pit drone behind the booth, so crouch-walk over to where you can sneak-shoot it with the pistol.
Get out the shockroach and start moving slowly along the down-sloping street. When you start hearing the sounds of shocktroopers fighting black ops guys, quickly run back up to the top of the street and wait. After the sounds stop, crouch-walk down the left side of the street to where you can sneak-shoot any shocktroopers who are on it.
After you sneak your way down to where you can just barely see into the big parking area past it, do a quicksave, then run forward to the spot that causes two black ops guys to rappel down from vents in the ceiling. That spot is on the raised right-side walkway at a point near the vents the guys drop down through. If you can't figure out where it is from my description, explore (and take fire) until you find it, then quickrestore and go straight for it.
As soon as you reach it, start strafing and running backward. Retreat all the way back up to the top of the sloping street to wait out the battle, then repeat the process of slowly sneaking and sneak-shooting your way down the left side of the street. If the voltigore sees you, run back up the street until it gets stuck trying to follow you, then shockroach it to death.
Move slowly through the parking area past the street to make sure it's enemy-free, then find the place in the back left corner that has several crates you can bash for supplies (after making sure there are no enemies hiding among the crates). Jump onto the nearby car's hood, then crouch-walk up into a vent area with an armor battery and an injured fatguard.
If you want to kill the fatguard for fun, whack him a few times with the wrench, then move on to the next section. In order to do that, enter the vent shaft that's in one wall and move along it until section of6a4 loads. (Then return to section of6a3 and splattify the dead fatguard's body if you want to.)
Section of6a4: THE BLACK OPS BOMB
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large Xen cave that's identical to the one in section of3a4 in a previous chapter, except that there aren't any armor batteries. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
Move along in the vent shaft until you come to another array of gratings with one of them open. After quicksaving, carefully drop onto the floor next to the grating, then turn so you can see the two black ops guys in the room ahead through the grating. They can't see through the grating, so if you don't crouch down or move out from behind the grating, they won't attack.
Get out the sniper rifle and slowly edge over to where you can see and snipe the black ops guy who's standing near a door over to the right. (Remember that you mustn't crouch yet, and that you can't shoot through the grating.) Turn to face the other black ops guy, who will be walking slowly toward you, then crouch and quickly snipe him before he can return fire.
Run around and bash all the wooden crates to find some C4 satchel bombs, then look near the large red storage containers for a box of SAW machine gun ammo. If you press up against the door that the first black ops guy was standing next to, the security guard on the other side will refuse to open the door until you turn off the nearby bomb. (As if that door would protect him if the bomb went off, the dumb clod!)
Look to the left of the security guard's door to find an open bit of fencing that you can go through. Crouch-walk along until you come within sight of the truck that the bomb is on, then quicksave before firing one of the displacer's BFG-like blasts at the black ops guy on the truck. That should kill both black ops guys in one shot. If it doesn't, quickrestore and try again (maybe aiming at a slightly different spot). After they're dead, run over and jump onto the truck, then face the bomb and use the "Use item" key to deactivate it.
Use the sniper rifle's zoom scope to read the bomb's handling instructions if you want to ("indispose the gravatronic rev limiter," indeed!), then go back to the security guard's door to be let in. Break the crate next to the guard to get an armor battery, then give the dippy guy a powered-up wrench whack to the head for being such a jerk.
Go down the hall to come to a large window through which you can see the G-Man on the truck, messing around with the bomb. It seems that he wants the Black Mesa facility blown up, but he'll at least wait until you finish off the big endgame monster before he lets the bomb explode. (But wouldn't the bomb kill the monster? Even if not, how would it matter after the whole facility is blown up? This situation doesn't quite make sense.)
Bash the crates near that window to find some displacer ammo, then move on to the lift room. Bash its crates and check its shelves, then get on the lift and use its button panel to descend to the Worlds Collide chapter.
Section of6a4b: SNIPING BLACK OPS GUYS
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a large Xen cave that's identical to the one in section of3a4 in a previous chapter, except that there aren't any armor batteries. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
After the lift stops, get out the sniper rifle and quicksave. There are a whole lot of black ops guys and gals in the area ahead, and most of them can be sneakily sniped. From the lift, crouch-walk slowly forward to where the path branches left, then turn to face that way.
Use night vision to help you see and snipe an assassin who's standing just past the corner of some huge wooden crates on the right side of the path. She can be seen just to the right of the column of round "Sierra mountain" symbols on a stack of red storage containers that are a bit behind her.
There's another assassin standing next to the right side of that stack of red storage containers, so crouch-walk along next to the crates on the left side of the path until you can see and snipe her. Now look straight ahead and continue to crouch-walk along next to the left-side crates until you can see and snipe a black ops guy.
Sniping him got the attention of two other nearby black ops guys. The one who's a bit behind and to the left of the guy you just sniped will fire his gun reflexively, but you don't need to worry about him yet. Turn to the right and watch the area where you sniped down the two assassins. A black ops guy will soon walk into sight over there, so snipe him the instant he does.
Move forward next to the left-side crates a bit more so you can snipe down the other black ops guy, then turn right and crouch-walk past the two dead assassins. As you move along, look to the left for a short sandbag wall between two huge stacks of wooden crates. There's a black ops guy on the other side of that sandbag wall that you need to snipe.
Yet another black ops guy is hiding behind the huge pile of wooden crates that are to the right of the sandbag wall. Sneak over to where you can snipe him, then go past him and around to the other side of the sandbag wall. Crouch-walk onward from there until you can turn right and see a metal crate. Stand up and use night vision and the zoom scope to help you see the head of a black ops guy over the metal crate.
Snipe him down, then crouch-walk slowly around the right side of a nearby small wooden crate to get to where you can snipe down the last black ops guy on this side of the incredibly noisy crate-moving track. (I strongly suggest you take your headphones off or turn your speakers off while playing this section, or you may never get that loud crate-moving sound out of your head!)
Bash the two nearby small wooden crates for health packs, then quicksave before running across the crate-loading track to the mounted gun. Use the mounted gun and immediately start up a continuous stream of fire aimed at the other side of the track, since two to four black ops guys will appear over there. Try to shoot them down without getting shot or grenaded. Quickrestore and try again if you need to.
Get the .357 ammo from the dark alcove near the mounted gun, then recross the track when the crates are stopped. Turn left and go down to the end of the track, then cross it again when the crates are stopped. Use the metal crates around the corner to jump onto the upper walkway, then crouch-walk quietly down to the walkway's other end.
There's a black ops guy in the lower-floor alcove on the left. Very slowly move up to where you can see the top of his head, then shoot it with the sniper rifle. (Or let him see you, then retreat and wait for him to run onto the track and get pushed along by crates.) Go back along the walkway to find two wooden crates that you can bash for ammo, then drop down into the black ops guy's alcove.
Move to the end of the alcove's little "extended niche" area, then wait for a crate to be moving right by you. As soon as the crate is past you, run forward to the small niche area that's ahead and on the other side of the track. Once you make it there, get out the RPG and quicksave.
Move as far left in your niche as you can while facing the room that's across the track and to the left a bit. There's a black ops guy on that room's upper floor, and you want to injure and distract him with a rocket. Right after a crate goes by, fire a rocket toward the upper half of the part of the room that you can see, then swerve it right at the last second. You should see it explode against one of the big wooden crates that's on the room's upper floor.
Wait for another crate to go by, then quickly run across the track and into the room. If the black ops guy on the upper floor is facing left and doesn't see you, then your rocket ploy worked, and you can easily shoot him down with the sniper rifle. If he does see you, quickrestore and try again.
Bash all the small wooden crates on your floor to find AR grenades, then get on the little lift and use its button panel to ride it up. Bash the crates near the top of the lift for a health pack, then crouch-walk over toward the dead black ops guy. Get the sniper rifle out and turn night vision on, then slowly sneak to where you can shoot the other black ops guy, who's standing a ways down the path through the crate stacks.
Crouch-walk along the path until you come to a room with a large fallen-over wooden crate in the middle of it. There's a black ops guy behind that crate, plus another one over to the right. What you want to do is sneak to where you can snipe the one who's to the right, then watch for the other one to walk out from behind the crate, sniping him as soon as he comes into view.
Bash the smaller wooden crates in the room for some health and armor, then walk onto a stack of two wooden pallets to get some SAW machine gun ammo. From on those pallets, jump to the nearby metal crates, then carefully crouch-jump onto the nearest corner of the large fallen-over wooden crate. From there, jump to the higher metal crates.
Crouch-walk along them until you get to where you can jump across to a large wooden crate with a wooden pallet on top of it. Get on the pallet and jump to the nearest metal crates, then turn right and jump over to some more metal crates. Get onto the two-pallet stack, then jump onto the tall wooden crates next to it.
Go along them until you can jump over to a double-wide crate top, then jump from it to a single crate top that's next to a short walkway. Crouch-walk along the walkway until you hear the sounds of black ops guys fighting aliens in the large room ahead, then retreat back to the crate top.
Wait until the sounds of battle stop, then get out the spore launcher and crouch-walk up to the edge of the walkway and look down to the big room's floor for targets. Take out any voltigores you see first, then target shocktroopers. If a voltigore or trooper keeps running around, the spore launcher's pods probably won't be fast enough to hit it, so switch to the .357.
While you're doing this, more aliens may teleport in. If this happens, back off, since more black ops guys will run in from the back. Wait until the new round of fighting is over, then repeat the process of looking into the room and firing spore pods, .357 slugs, shockroach zaps, etc. at surviving aliens. (If the new wave of fighting doesn't happen right away, wait out of sight until it does.)
If you can't see any more aliens on the room's floor (even with night vision and the sniper rifle scope), but you can hear some, try tossing hand grenades around to see if you can scare them up. If you run out of grenades, you can go back to the crate top that's adjacent to your walkway, turn right, and drop onto a small wooden crate that you can bash for grenades. Unfortunately, you'll then have to drop to the floor and repeat the process of hopping all the way up to where you can toss the grenades into the aliens' room.
When you think the room is clear, quicksave, then jump over to the nearest swinging crate. From there, jump-crouch to the other swinging crate when it's fairly close, then turn right and jump onto the top of the large red storage container stack. Crouch-walk all along its edges and survey the room to see if you can find any more targets to shoot down.
Jump to the large metal beam with all the black and yellow stripes on it, then turn left and go down to where you can jump to a nearby wooden crate stack. Jump across to another wooden crate stack, then drop your way carefully down from there until you reach the floor. Bash the small wooden crates to find health packs, then go to the back of the room and up a ramp to find more crates to bash.
A security guard will open the large nearby door, giving you access to a great supply area. Bash all its crates, check all its shelves, and use its first aid and HEV wall stations to get ready for the big final battle. Wrench-whack the guard for fun if you want to, then get on the huge lift and use its button to descend to section of6a5.
Section of6a5: THE ENDGAME BOSS MONSTER
DISPLACER NOTE: Using the displacer's altfire mode anywhere in this section will take you to a new rocky platform area in Xen. Jump from your starting platform to the next-lowest one to find an ammo canister, then run and drop (don't jump) to the lowest platform to find the exit portal. As with previous sections, the exit portal will take you to varying locations, depending on exactly where you were when you used the displacer's altfire mode.
When you descend to the windy chamber, wait for a couple of wooden crates to be blown back to you, then bash them for ammo. Run against the wind until you can drop down to some stairs that are beneath it. Past the bottom of the stairs, bash the two wooden crates for ammo, then push the metal barrel over next to the small door in the wall that has a wheel in its center.
Jump-crouch onto the barrel, then crouch-walk through the door. Run to the back of the room beyond to find two armor batteries which you hopefully won't need yet, then crouch-walk back through the door and drop to the floor. Go over to the button-opened door in a nearby corner and use its button so you can go through it.
Past that door, find the ladder with green gunk blocking its top, then climb the rope that's near it. When you're at the top of the rope, swing it toward the upper walkway, then jump to get onto it. There's a small healing pool down at one end of the walkway that you'll want to remember for later.
Follow the walkway into the big room with the huge purple vortex thingy. Go across to the walkway section where two alien plants are growing high up on a wall and use your barnacle weapon to pull yourself up to those plants and resupply on pods.
When the big boss monster comes out of the purple vortex, run around to where you can hide from it behind the wall, near the top of a ladder. Peek out to let it see you, then duck under cover when it starts breathing poison gas at you. As soon as it's through doing that, run toward it, but then back away as it swings its tentacles at you. After that, run forward and turn left to find a laser mounted on the railing.
Quickly use the laser to shoot out the monster's nearest eye, then run back around the wall for cover. Peek out until the monster starts up another gas attack, then hide from it. The instant it's over, run across to the mounted laser on the right side of the room. Dodge back as you first approach the laser to avoid getting whacked.
Use the laser to shoot out the monster's other eye, causing a weird pouch in its "stomach" to open up. Inside the pouch is a glowing energy orb, but despite what every other Opposing Force walkthru in the world says, that's not what you need to shoot. You need to instead shoot through the energy orb so that you're hitting the vulnerable back wall of the pouch.
One way to do that is to use a weapon that does radius damage, like the spore launcher. Get it out and move back to where you can see at least part of the pouch's back wall through the orb. Shoot pods into the pouch until the monster roars loudly and rears way back, which indicates that you've succeeded in scoring a critical hit against it. Another way is to stay at the laser and fire it repeatedly at the energy orb, or just a bit to the right of it. That can get you a pretty quick critical hit, too.
After that, you'll need to use the following nine-step process to score three more critical hits to defeat the monster.
1) Run over to the mounted laser on the left side of the room. If the bridge that connects the two walkway sections is out, use your barnacle weapon on the alien plants to pull yourself across.
2) Quicksave, then man the laser and shoot out the monster's nearest eye as soon as it opens.
3) Run for the ladder that's on the other side of the walkway, keeping to the right as much as you can to prevent the shocktrooper that teleported in on the walkway below from seeing you.
4) Climb down the ladder with the SAW machine gun out, then wait and see if the shocktrooper runs into view. If it does, quickly kill it and its shockroach with the machine gun. Otherwise, get out the sniper rifle and carefully crouch-walk over to where you can snipe the shocktrooper right in its eye for an instant kill, then back up and wait for the shockroach to die.
5) Make the run across the walkway that leads to the room with the rope, then climb up the rope.
6) Stand in the healing pool to heal if you're at less than 100 health. If your armor rating is less than 60 or so, climb down the rope, go through the button-opened door, and return to the secret room with the armor batteries in it. Get them, then go back through the button-opened door and climb the rope again.
7) After quicksaving, go over to where you can see into the monster's room, and wait next to the corner for it to start up a gas attack. When it does, quickly strafe right for cover.
8) As soon as the gas attack is over, run over toward the nearby mounted laser, but don't go quite up to it yet. Wait a couple of seconds to see if the monster will swing its tentacles at you, which it usually (but not always) does. Back up quickly if you see the tentacle swing coming, then run up and man the laser.
9) Shoot out the monster's other eye, then either continue firing the laser into the open pouch, or get out the spore launcher and back up along the left railing until you've got a pretty good view of the pouch. Fire the laser or spore pods at the pouch's back wall until the monster roars loudly and rears way back. When it does, you've scored another critical hit, and should quickly return to step 1 (if that wasn't the final critical hit).
Once you make the final critical hit, just stand and wait to be teleported to the Conclusion chapter.
Section of7a0: G-MAN FINALE
This "chapter" is just like the Endgame chapter in Half-Life. You've been stripped of all your weapons, and all you can do is look around as the G-Man yaks at you. This time, you don't even get to make a bogus choice -- you just get put on ice indefinitely.
This document was provided to GameBoomers.com and may not be distributed without express written permission of the author and the content may not be altered in any way.
GameBoomers Walkthroughs and Solutions