British army captain Leith (Richard Burton) is handed a mission that may prove to be his most difficult yet: He must partner up with fellow military officer Brand (Curd Jürgens), with whom he doesn't get along, to steal top secret documents from a Nazi group in Libya. Complicating matters further is Leith's relationship with Brand's wife (Ruth Roman), with whom Leith once had a torrid love affair, ratcheting up the tension between them.