Bob Sharkey, an instructor of would-be spies for the Allied Office of Strategic Services, becomes suspicious of one of the latest batch of students, Bill O'Connell, who is too good at espionage. His boss, Charles Gibson confirms that O'Connell is really a top German agent, but tells Sharkey to pass him, as they intend to feed the mole false information about the impending D-Day invasion.

James Cagney
as Robert Emmett 'Bob' Sharkey

Annabella
as Suzanne de Beaumont

Richard Conte
as William H. 'Bill' O'Connell

Frank Latimore
as Jeff Lassiter

Walter Abel
as Charles Gibson

Melville Cooper
as Pappy Simpson

Sam Jaffe
as Mayor Galimard

Karl Malden
as Jump Master (uncredited)

Judith Lowry
as Peasant Woman (uncredited)

Reed Hadley
as Narrator (voice) (uncredited)
CinemaSerf
James Cagney leads quite an efficient cast in this superior WWII espionage thriller. He heads a special outfit (077 not 007) charged with helping the resistance. The curious thing is that he, and the audience, know that he has a spy in the midst of his team - and we all now exactly whom that person ...