John "Kit" McKittrick (John Garfield) endured two years of brutal torture after being captured in the Spanish Civil War. However, he managed to withhold the vital information sought by his captors, particularly their leader, a never-seen Nazi Germany with a limp. His lifelong friend, Louie Lepetino, arranged his escape. When Louie, a New York police lieutenant, dies under suspicious circumstances, Kit ends his convalescence in Arizona and returns to the city to investigate. At the end of the trip, he bumps into attractive fellow passenger Toni Donne (Maureen O'Hara).