First, you have to use the PDA to hack into the US Military database to get info on defusing a bomb. This network puzzle is a little trickier than the previous ones. Did you read the manual? The section on 'Components' describes three different kinds of mirrors - single, double and fixed. Specifically, a double mirror reflects data streams on both sides. Look closely at the mirrors in this puzzle to note that there are two double mirrors, albeit that you only need to use one of them.
 

 
Next read the downloaded field notes on defusing bombs. After reading the 'Self Protection' section, the 'rubber gloves' dialog topic is activated with Mark, so ask him for them. In the notes on 'Defusal' you learn:
a)

 

The wire from the negative terminal of the battery to the trigger box must be bridged with that from the positive terminal of the battery to the trigger itself

b)
 

After bridging these two wires, cut the wire that runs from the trigger box to the timer

 

SOLUTION

 

 

a)

The paper clip is ideal for bridging wires.

b)
 

While holding the paper clip select the wire from the negative terminal of the battery to the trigger box, marked (1) in the diagram

c)This wire must be bridged with the wire marked (2) in the diagram
 

Shown as 'Live Trigger Wire' in the game
d)Note that you can also select wire (2) and bridge it with wire (1)
 

Shown as 'Negative Wire to Trigger Box' in the game

e)
 

After wires (1) and (2) are bridged, use the knife to cut the wire from the trigger box to the timer, marked (3) in the diagram