The story picks up as Dominey is found severely ill in the Dakar jungle and is brought into his old college buddy's camp, where he heals from his injuries. One night when they are in the jungle camp together, England declares war on Germany and they conclude that they are now each other's enemies. Ragenstein orders his right hand man, Dr. Schmidt (Ludwig Stössel), to kill Dominey, and sets out on a long journey to London to impersonate Dominey and spy for the Third Reich. Some time later, the German High Command sanctions Ragenstein's mission to go undercover into Britain and infiltrate the English upper ranks. His first task is to find out the defence plans for the English channel. He meets with another German agent, Frederick Seamon (Henry Daniell), who is a native Brit. Ragensteins sets out to get the plans from a relative to Dominey's wife, Sir Ronald Clayfair (Aubrey Mather), who is the British Minister of Home Defense. By pure chance, Dominey's wife, Lady Muriel Ingram Dominey (Evelyn Ankers), spots Ragenstein, whom she believes to be her husband, at a restaurant in London, and introduces him to Sir Ronald, who invites him to dinner. At the dinner, Sir Ronald offers him a position with the Home Defense. Unfortunately Ragenstain is recognized as himself at the dinner, by an old friend and mistress, Baroness Stephanie Idenbraum (Kaaren Verne), whom he has to socialize with to avoid suspicion. Lady Muriel sees her husband with the baroness and confronts her "husband" about it. Ragenstein makes up a story and tells Lady Muriel that the baroness just mistook him for another man. Captain Francois Bardinet (Edward Norris) of the French Consulate, who is a guest at the dinner, claims that the baroness' husband was killed in a duel a few years ago by an unidentified, mysterious lover. Lady Muriel is still baffled by her husband's new and improved behavior. It turns out that Bardinet is a German spy who has had an affair with Lady Muriel. Seamon tells Bardinet to step back and let Ragenstein court his "wife" so that they can get their hands on the plans. Bardinet gets jealous and sabotages Ragenstein's relationship with Lady Muriel, telling her that he has seen him court the baroness on a previous occasion.