October 1962, at the peak of the Cuban Crisis. CIA-agents force Joshua Mansky, a math genius, former professor at Princeton with a drinking problem and a former chess prodigy out of retirement as he is the only one to replace the severely ill US contender in a chess tournament against the Soviet champion Gavrylow in Warsaw with any chance of winning.
In Warsaw, the Russians use every trick in the book to distract Mansky after he wins the first match despite being blind drunk. One of the agents who babysit Mansky dies right in front of him. The tournament turns out to be a cover for gathering intel from an informant, a Soviet officer with the codename Gift. Only he can confirm whether the Russians really have nuclear warheads stationed in Cuba. Gift is in Warsaw for a conference of the Warsaw pact. The only one who knew Gift personally is the dead agent.
The Americans are in danger of losing both games – the chess game and the one for world domination. They will have to start playing dirty, too.