GSC Game World and Valve have announced that S.T.A.L.K.E.R.: Clear Sky will be available for digital download worldwide exclusively on Steam. The official prequel to the survival FPS game S.T.A.L.K.E.R.: Shadow of Chernobyl is currently slated for simultaneous release on Steam and at retail outlets later this year. The story of the game brings the players one year prior to the events of the original S.T.A.L.K.E.R. game in 2011. The protagonist is a mercenary who appeared at the edge of the opposition between stalker factions, Strelok and even the Zone itself. The main character will have to play the key role in the events, which led to creation of the Zone up to the point from which the original S.T.A.L.K.E.R. game begins. Twelve new screens have been inserted in our gallery.