The Spy in Black

In 1917, during the World War I, Captain Ernst Hardt is assigned to travel to the Orkney Island to meet his contact, Fraulein Thiel, to receive orders. Meanwhile, the new schoolteacher Anne Burnett is intercepted by German spies and thrown off cliffs to look like an accident. Thiel poses of Anne Burnett and tells Capt. Hardt that the German submarine fleet should attack and destroy the British Fleet with the support of the rogue British Officer Ashington, who lost his position of Commander due to drink problem and is attracted by Thiel, who is his lover. Out of the blue, Burnett's fiance Rev. John Harris arrives at her home to visit her but is subdued by the spies and made prisoner. Thiel keeps Capt. Hardt locked in his room during the night for her protection, and he tells his fellow officers in the submarine the plan to destroy the British Fleet. During the night, the lures Burnett and escapes from his room. He sees Burnett meeting Ashington and overhears their conversation, learning that the plan is indeed to destroy the German U-Boat fleet. Now he needs to contact his submarine to disclose the real plan, but the British soldiers are hunting him down.