After his release from the asylum, to celebrate his return to the real world, Neale visits a local carnival, only to accidentally receive the "prize" of a cake which was meant for a Nazi agent. When he discovers the error, he turns for help to a detective, whose investigations only serve to make the situation more complicated. Neale soon winds up on the run from both the Nazis and the police, who mistakenly believe him guilty of murder. He is led to Scotland Yard, where his fate entwines further with a Nazi front organization, and an unlikely love affair.