Renowned big-game hunter Captain Thorndike (Walter Pidgeon) is hunting in the Bavarian forest when he stumbles upon Adolf Hitler's vacation residence. Tempted by the idea of assassinating the dictator, he's apprehended and beaten before escaping and stowing away on a steamship back to England. Onboard, Thorndike has his identity stolen by the smooth-talking con man Mr. Jones (John Carradine). Both men soon discover that Gestapo agents are swarming London, looking for the would-be assassin.