S.T.A.L.K.E.R.: Clear Sky is a survival FPS game for PC based on a 'what-if' scenario of the second Chernobyl Nuclear Power Plant accident. The game is created as a warning to mankind against mindless play with technologies. S.T.A.L.K.E.R.: Clear Sky is the official prequel to the renowned S.T.A.L.K.E.R. game by the Ukraine-based GSC Game World studio. The game is set in 2011 and brings forth the events to have preceded the third campaign of Strelok to the Zone center. S.T.A.L.K.E.R.: Clear Sky introduces an alternative look onto the events of the original game and offers the player to try himself out as a mercenary s.t.a.l.k.e.r. in search of his own path in the world of S.T.A.L.K.E.R.