The Spy in Black

The Spy in Black US UBoatis a 1939 British film, and the first collaboration between the British filmmakers Michael Powell and Emeric Pressburger. They were brought together by Alexander Korda to make the World War I spy thriller by Joseph Storer Clouston into a film. Powell and Pressburger eventually made overfilms during the coursde of their partnership.

Captain Hardt Conrad Veidt, a World War I German Uboat commander, is ordered to lead a mission to attack the British Fleet at Scapa Flow. He sneaks ashore on the Orkney Islands to meet his contact, Frau Tiel Valerie Hobson. Tiel has taken over the identity of local schoolteacher, Anne Burnett June Duprez, who had been kidnapped by German agents. Hardt finds himself attracted to her, but Tiel shows no interest. The Germans are aided by a disgraced Royal Navy officer, the former Commander Ashington Sebastian Shaw who, according to Tiel, has agreed to aid the Germans after losing his command due to drunkenness, and Tiel implies that she has slept with Ashington to obtain his cooperation.The plan is almost disrupted when Burnetts fianc, Rev. Matthews, arrives unexpectedly, but the spies take him captive there is another small complication when the local minister who had already met Matthews comes to the house, but Tiel manages to get them to leave. Now equipped with the crucial information he needs about the fleet movements, Hardt makes rendezvous with his submarine to arrange the attack. Returning to the house, and confident that all is going to plan, Hardt make advances to Tiel, but she rebuffs him. She leaves the house, believing she has locked Hardt in, but he gets out and secretly follows her, discovering that she has gone out to meet Ashington. Hardt overhears them talking and learns the truth the British are fully aware of his presence and his mission, and his contacts are really British doubleagents Ashington is in fact RN Commander Blacklock, and Frau Tiel is Blacklocks wife, Jill. ........

Source: Wikipedia