S.T.A.L.K.E.R.: Clear Sky is set in 2011, one year prior to the events of the original S.T.A.L.K.E.R. game.
What new challenges await stalkers within the depths of the new zone? Why do anomalous outbursts continue to rattle the Zone, and what can be done to stop them? Which faction will take the upper hand in the Factions War? These and many other questions will be answered in the official prequel - S.T.A.L.K.E.R.: Clear Sky.