"Based on a composite of actual incidents during WWII, the Office of Strategic Services sends teams of spies and saboteurs in Nazi-occupied France and Nazi Germany.."
The (O)ffice of (S)trategic (S)ervices' Cmdr. Brady (Patric Knowles) forms Operation "Applejack" (based on a composite of actual incidents during WWII) and sends Lt. (j.g.) Philip Masson, U.S.N.R. aka John Martin as spy Philippe Martine (Alan Ladd) along with Miss Ellen Rogers posing as her college roommate, Madame Elaine Duprez (Geraldine Fitzgerald) and Robert Bouchet, Tech Sgt., A.U.S. as Albert Bernardito (Richard Benedict) to acquire secret Nazi plans. After nearly getting caught they succeed and get new identities. However they discover a secret that could change the war and risk their lives to get the information back to London before it jeopardizes their lives.
John Martin / Lt. (j.g.) Philip Masson, U.S.N.R. / Philippe Martine

Miss Ellen Rogers / Madame Elaine Duprez

Cmdr. Brady

Col. Paul Meister

(W)omen's (A)rmy (C)orps Radio Operator Mary

Frank Schmidt (O)perational (S)upport (P)ackages, (M)aterial, Maintenance, Management, U.S.N.R. / Parker

Robert Bouchet, Tech Sgt., A.U.S. / Albert Bernardi

Amadeus Brink

Rodney "Gates" Parrish / Raoul Josse

Field

Col. Crawson

Marcel Aubert

Gen. Donovan

Gerard

Madame Prideaux

Arnheim

Claudette (uncredited)

German Radar Captain (uncredited)

Electronics Engineer (uncredited)

German Soldier (uncredited)
American Soldier (uncredited)
MP NCO (uncredited)