Scream your face off it's System Shock 2 back from the dead and available on Good Old Games.
System Shock 2 costs $9.99 on GOG.com and is available for Windows. Included are a separate soundtrack (FLAC and MP3), the original pitch document, some artwork, a radio interview with Ken Levine, a wallpaper, some avatars and a manual.
System Shock 2 development was commanded by Ken Levine, he of BioShock fame. It's considered a forefather of BioShock, and is lauded around video game parts as very important indeed.
It's also very scary, but you can ease the frights by playing with up to three friends co-operatively.
Studio Night Dive restored this treasure of 1999, and talked to Rock, Paper, Shotgun about the game's place in history earlier this week.