Oxford, England, 1939 on the eve of the United States entering World War 2, the Germans have a new secret weapon, a magnetic water bomb that is pulled to a ship and explodes. The British want to know more about how it works and pull in American scholar Richard Myles (Fred MacMurray) to obtain information undercover in the Father land. Richard has just married classmate Frances (Joan Crawford) and the two take off for a private honeymoon on the coast. Before they know it they have agreed to be spies and take off to Germany, Frances with a rose in her hat to signal their presence to an unknown contact who will give them further information on who the main contacts in the country will have information about the destructive weapons of Germany. When they have landed they are contacted by suspicious Hassert Seidel (Conrad Veidt) who leads them to a hotel where another contact gives them more information about a concert with information located in the musical notes, which have been secluded in a tourist guide book. Richard makes friends with fellow Oxford scholar Thornley (Bruce Lester) and the three Americans are thrown together when someone shoots a high-ranking official at a Franz Liszt concert stopping the proceedings for questioning from the Nazis. At the concert disruptions Richard meets another Oxford chum, Sig von Aschenhausen (Basil Rathbone) whose place in Germany is unknown to the Americans until they realize that he is a Nazi himself, and aware of a contingency to gather information back to Britain. Aschenhausen is the perfectly sever German and he kidnaps Frances and tortures her to get information, thus putting Richard, Thornley, and Seidel into action to try to free her, and get back to the land of the free.
Who have a new secret weapon, a magnetic water bomb that is pulled to a ship and explodes?
The Germans