S.T.A.L.K.E.R.: Clear Sky is a prequel to its survival FPS S.T.A.L.K.E.R.: Shadow of Chernobyl, bringing the players one year prior to the events of the original S.T.A.L.K.E.R. game in 2011. Steam's "Coming Soon" title list indicates that we may see the second installment in GSC World's action game in May.