Mike McDermott (Matt Damon) loses his money in a poker game against Russian gangster Teddy "KGB" (John Malkovich). Under pressure from his girlfriend, Jo (Gretchen Mol), he promises to quit gambling. This lasts until his friend, Lester "Worm" Murphy (Edward Norton), gets out of prison and needs to pay off an old debt. The pair come close to earning the money back but are caught cheating. Then Mike finds out the debt is owed to Teddy and makes one last-ditch effort to beat the Russian.