During a performance at the Moscow Circus, Harry Palmer is secretly approached by an agent from the International Atomic Energy Authority and given a big, priority assignment to locate and recover a shipment of Plutonium stolen by an unknown terrorist group. The trail leads Harry and his young field assistant, Nick, to St. Petersburg. That night at a restaurant, Harry, Nick, Tatiana, Nick’s ballerina girlfriend, and her father, curator of the Hermitage, are having dinner. Suddenly masked gunmen enter the restaurant, spraying bullets everywhere. They kidnap Tatiana. The next day, her father is given an ultimatum: Tatiana’s life in exchange for treasured paintings from the Hermitage. To recover the stolen Plutonium and find Tatiana, Harry puts his life on the line and asks for help from his arch-enemy Yuri, the Mafia boss of St. Petersburg. In an uneasy alliance, Harry finds himself caught up in a complex web of distrust, double dealing, betrayal and murder leading to a final showdown that only one can win.