Once Upon a Honeymoon (1942)

At the dawn of WWII, Katie O'Hara (Ginger Rogers), an American burlesque girl hellbent on climbing the social ladder, marries wealthy Austrian, Baron Von Luber (Walter Slezak). Pat O'Toole (Cary Grant), an American radio reporter, sees this as his chance to investigate Von Luber, who is suspected of having links to the Nazi party. As the Nazis blaze across mainland Europe, O'Toole follows O'Hara for the story, but soon falls in love. When Katie learns that her husband is indeed a Nazi, she fakes her death and runs off with Pat to become a spy and turn against Von Luber...