Forced to put aside Cold War hostilities, CIA agent Napoleon Solo and the KGB's Illya Kuryaki team up on a joint mission to stop a mysterious international criminal organisation which is bent on destabilising the fragile balance of power through the proliferation of nuclear weapons and technology. The duo's only lead is the daughter of a vanished German scientist, who is the key to infiltrating the criminal organisation, and they must race against time to find him and prevent a worldwide a catastrophe.