Stalker was incredibly lucky: he obtained a rare and valuable artifact "Heart" in the Zone. His younger brother, nicknamed Nimble, was even luckier - he received a tip on a larger target. There is no time to plan a trip. Without waiting for his brother's consent, Shustry sets off to the goal alone. To save his unlucky brother, Stalker is forced to return to the Zone, where his new artifact begins to exhibit unexpected properties. Breaking through military cordons, gangs of marauders and mutants, Stalker encounters something more dangerous than anything he has seen before.