When an Allied prisoner of war ship transporting a cargo of German prisoners is torpedoed by a German submarine in the North Atlantic, three survivors cling for their lives to a raft. The three are German prisoners of war Corporal Karl Richter, Private Heinrich Krause and British interpreter Roland Cheever. Cheever, who was wounded in the explosion, is vulnerable and defenseless, and so the predatory Richter decides to assume his identity. After stripping the helpless Cheever of his uniform and identity papers, Richter dumps his body into the sea. Some time later, Richter and Krause are rescued by a passing ship, and Richter awakens in a hospital near the Midland Prisoner of War Camp. The papers found on his body identify Richter as Cheever, and so the hospital staff assumes that he is a British soldier and ally.