Nicholas Van Orton (Michael Douglas) is a successful banker who keeps mostly to himself. When his estranged brother Conrad (Sean Penn) returns on his birthday with an odd gift -- participation in a personalized, real-life game -- Nicholas reluctantly accepts. Initially harmless, the game grows increasingly personal, and Orton begins to fear for his life as he eludes agents from the mysterious game's organizers. With no one left to trust and his money gone, Orton must find answers for himself.