A Spanish Civil War veteran who survived years in a prison camp comes to New York on a mission to find out who murdered his friend. His investigation is threatened by Nazi spies, who want to get their hands on secret information he learned during his captivity. Mystery, starring John Garfield and Maureen O'Hara.

Imprisoned during the Spanish Civil War, John "Kit" McKittrick is released when a New York City policeman pulls some strings. Upon returning to America, McKittrick hears that a friend has committed suicide, and he begins to smell a rat. During his investigation, McKittrick questions three beautiful women, one of whom has a tie to his refugee past. Pursued by Nazi operatives, McKittrick learns of the death of another friend, and begins to suspect the dark Dr. Skaas.