You can buy all five games on GOG; they sell a bundle for the first four games here. They sell the fifth game in the series separately.

If you just want the first game, Big Fish sells it here.

If you REALLY want to delve into Blackwell, the very first game that inspired the full series of commercial games was a freeware game called [b]Bestowers of Eternity[//b]. AFAIK only "Part One" was made, and then Dave shelved further development of that in favour of creating the first Blackwell game as a commercial venture.

BoE is still available as freeware and it's interesting to see what started it all off.

http://www.adventuregamestudio.co.uk/site/games/game/304/

Thus began Wadjet Eye Games... and the rest is history!

(Just checked the link, the main download didn't work but the AGS Archives one did. Can't beleive I played that game over 12 years ago!!! :O)

Hope you enjoy the games if you decide to get them. I got the first four for only a couple of dollars during a big GOG sale. I bought the fifth at full price when it came out, as I wanted to support the developers. Plus I wanted to find out what happened right away. They are fantastic games.