A lone stalker guides a team of scientists into the heart of the Chernobyl exclusion zone. Their goal is to discover the secrets behind the deadly anomalous energy explosions that continue to ravage the zone in the years following the second (and fictional) Chernobyl meltdown. These burnt plains of the Ukraine are littered with aggressive mutant animals, pockets of impassable radiation, and factions of humans willing to kill for valuable irradiated artifacts. Only a seasoned stalker, mercenary hunters of this forsaken landscape, can guide these scientists through unscathed. In the distance, a thundering rumble grows closer, shaking the earth. The stalker halts the scientists as the sky turns blood red. The area suddenly explodes with deadly energy. The scientists are obliterated. The stalker, somehow, survives.

　　Nothing cheers up a post-apocalyptic nuclear wasteland like a little kumbaya.

　　Thus the stage is set for S.T.A.L.K.E.R.: Clear Sky, a prequel to the celebrated S.T.A.L.K.E.R.: Shadow of Chernobyl. This first-person shooter/role-playing hybrid is set a year before the events of Shadow of Chernobyl and puts you in control of Scar, a mercenary stalker that has somehow become immune to the anomalous energy waves that threaten all life in the exclusion zone. The exclusion zone is open for you to explore as you see fit, allying with factions and playing through the main storyline or simply collecting valuable artifacts to upgrade your abilities and fill your wallet. As always in S.T.A.L.K.E.R., how you play is entirely up to you.

　　Gallivanting around the exclusion zone isn't going to be easy. There are other stalkers and clans out there, each with their own goals and agendas. Quite often, your goals will clash. For example, you'll seek to collect a powerful artifact while a rival stalker may simply want to kill you. You can see the conflict here. What's impressive is that the clans will operate independent of your actions and non-player characters will fight their own battles in this large, open world.

　　GSC Game World gave us an updated look at Clear Sky in action, walking us through one of game's largest open areas: the marshland. We spoke quickly with a friendly clan leader who directed Scar to save a stranded comrade that was being hunted by wild, irradiated boars. Before leaving the friendly confines of the camp, Scar shared some friendly words with other clan members--almost every character in the game has something to say--and then purchased a new shotgun from a weapons dealer. The inventory system works much like that of Resident Evil 4--you have a limited number of slots to store guns, ammo, and artifacts. Choose wisely.

　　As we left the base camp, a group of clan members came along to help out. Since we last saw Clear Sky, GSC Game World added some rudimentary squad commands. They are limited to "attack" and "take cover," but they were nonetheless effective as we ran into a group of bandits hunkered down in an abandoned house in the middle of the marshland. After ordering the squad to take cover, we moved into a good cover position and ordered it to open fire, gaining the element of surprise. We quickly dispatched the enemy, took out a few mutant wild boars, and rescued our friend.

　　We only saw the shotgun in action, but there will be plenty of interesting weapons, such as one-handed machine guns and old Red Army firearms. Keep in mind that Clear Sky takes place in 2011, so you won't be wielding any giant radiation guns of the future here. Weapon will degrade over time, and you will have to maintain them to keep them from jamming--not something you want to have happen as a mutant boar bears down on you.

　　In addition to Deathmatch, Team Deathmatch, and Artifact Hunt from the original Shadow of Chernobyl, GSC Game World is adding a new game type to the 32-player multiplayer mode. The development team was scant on details but did say the new mode will be similar to a traditional Capture-the-Flag. We're hoping some of the role-playing-game elements of the single-player game make their way to multiplayer, including customizable clothing and weaponry, but we won't know more until the E3 Media & Business Summit where the game will be shown later this summer.

　　Many of the buildings are modeled after real-life structures in the exclusion zone.

　　So far, Clear Sky is looking to expand upon the winning formula that made Shadow of Chernobyl a critical hit last year. While the post-apocalyptic, nuclear wasteland instantly draws parallels to the venerable Fallout franchise, Clear Sky's blend of tactical combat, role-playing elements, and dynamic storytelling looks to carve out a niche all its own. We'll have more on Clear Sky soon.