GSC Game World has announced a prequel to this year's surprisingly solid FPS S.T.A.L.K.E.R. The game is set one year prior to the first game, and takes place in the heart of Chernobyl, inside the Zone - the area in which a nuclear disaster has destroyed almost all life and created a number of mutated creatures.

Passage through the Zone is unsafe but new areas have been found that may provide clues on how to end the problems. As a mercenary named Strelok you must choose a side in a brutal battle and explore the Ref Forest, Limansk and the Pripyat Undergrounds. GSC Game World also claim that the AI has been improved over the first game, making combat feel more realistic.

The prequel to S.T.A.L.K.E.R., titled S.T.A.L.K.E.R.: Clear Sky is due for release on PC in Q1 2008.