Clive Barker's Undying
The official Undying website was http://undying.ea.com
But don't bother. All you'll find there is a redirect to the latest set of ads for the current flavor of the day game. They pulled the undying trailer from their site. Shame. I went straight to the store after seeing it. Get the trailer here. (36M exe.) Or youtube for it.
Undying was arguably one of the best FPS of it's time. Utilizing the Unreal engine, the Undying team blended suspense, creepiness, creativity, gameplay and masterful storytelling into one of the most immersive and spooky FPS releases ever.
Here is the index to hundreds of undying screenshots. Mostly in game order, and shows probably 30% of the game areas, or ideas. (complete with unfinished sections. The game industry was learning what would happen when the sales team expectations weren't matched up with reality) Enjoy.