If you're looking to take another trip to the irradiated wasteland of Chernobyl, you don't need to book a plane ticket. GSC Game World's Sergey Grigorovitch has revealed that they're working on an add-on to the open-world shooter and confirmed that a sequel was planned as well.

S.T.A.L.K.E.R.: Shadow of Chernobyl and its prequel S.T.A.L.K.E.R.: Clear Sky take place in an alternate history in which there was a second disaster at Chernobyl which killed or mutated all of the animals and humans in the area, now dubbed "The Zone". Various factions (military, scientific, etc.) now battle for control of the Zone. The post-apocalyptic setting and open-world elements bring to mind Fallout 3, though it's much closer to a shooter than an RPG.

According to ClanBase, Grigorovitch revealed in an online chat that GSC was currently working on Call of Pripyat. He referred to it as the "second expansion," which means it will likely be a standalone installment like Clear Sky. Pripyat was the name of a city that appeared in both previous S.T.A.L.K.E.R. so it looks like this game will be set in The Zone as well. Pripyat will be released this fall.

It's not clear whether Pripyat will be set before or after the events of Shadow of Chernobyl. Given the multiple-branched ending of Chernobyl, though, GSC might just wait until the sequel to chronicle that game's aftermath. Grigorovitch apparently also mentioned that S.T.A.L.K.E.R. 2 was in development but no information was revealed about the project.