S.T.A.L.K.E.R.: Call of Pripyat takes PC gamers once again into the deadly area surrounding the Chernobyl nuclear reactor explosion of 1986. Cordoned off by the military, this highly contaminated "Zone" is scoured by treasure hunters known as S.T.A.L.K.E.R.s, who search the irradiated lands for unique artifacts. In the role of Agent Alexander Degtyarev, the player must go undercover as a S.T.A.L.K.E.R., investigating the mysterious disappearance of five military helicopters while standing against various S.T.A.L.K.E.R.groups.