Veteran British secret service officer John Pedley, irritated that he has never been knighted, decides to hijack a government shipment of $15 million in gold ingots being flown from Zurich to Tanzania via Italy. He contacts an American acquaintance, writer Mike Warden, who has recently lost his university position because of his pacifist political views, and lures him to Venice on the pretense of introducing him to an interested publisher; instead, Mike is introduced to Sylvia Giroux, Pedley's accomplice, and persuaded to help organize the heist. While Pedley directs the operation from London, Sylvia and Mike make the necessary arrangements in Italy: a Messerschmidt piloted by a former Luftwaffe officer will shoot down the plane carrying the gold, and ex-Fascist general Aldo Ferranti will sell the ingots after they have been smuggled to him. Pedley, who is ordered aboard the plane at the last minute by his superior, instructs the pilot to land the passengers safely when the Messerschmidt attacks. As the gold is carried away in three trucks, Pedley, whose motive for the hijacking is to capture Ferranti and thus prove his worth, quickly engineers the capture of two of the vehicles. Sylvia and Mike are arrested by Italian police as they escape in the third truck, but Pedley intervenes, claiming that Mike is his agent. After the two thieves exchange a package of ingots in return for half the compensation Pedley will receive from an insurance firm, the agent is finally invited to be knighted by the queen. Sylvia and Mike then make marriage plans.