The English blackmail a German expatriate into a Nazi rubber shipment.

Wealthy Robert Crain, a deserter from the German Army posing as a Swiss national in India during World War II, is coerced by British Intelligence Colonel Statter into masquerading as a Gestapo officer. Installing himself as a passenger aboard a German blockade runner which is carrying a valuable cargo of rubber from the Orient, Crain, using the name Hans Keil, is to deactivate the scuttling charges by which the captain would destroy the ship if faced with capture. Captain Mueller, unsympathetic to the Nazi philosophy, regards the presence of the "Gestapo officer" on his ship with fear and suspicion. Mueller refuses to allow Crain the run of the ship, thus making it almost impossible for him to find and deactivate the explosives before the Allies intercept the vessel at a predetermined point. Two German submarine officers bring aboard the freighter a group of survivors of a sunken ship, among them some American refugees and Esther Levy, a German Jew who has been the victim of Nazi atrocities. Crain, aware that his identity is about to be exposed by the suspicious submarine officers, decides to lead the new arrivals and some of the crew members to mutiny. By the time the Germans learn that Crain is a fraud, mutiny has broken out and the ship is sinking. Crain and Mueller, left alone on the ship, discover that the vessel probably will not sink for a few hours. Crain convinces Mueller that he owes no allegiance to the Nazis, and Mueller radios a nearby Allied ship to save them and the cargo.