RKO bought the film rights to Dorothy B. Hughes' novel for $15,000 expressly as a vehicle for Maureen O'Hara according to contemporary articles in The Hollywood Reporter.
RKO traded the film rights of Of Human Bondage (1934) and The Animal Kingdom (1932) with Warner Bros. for the services of John Garfield for this film and for Joan Leslie in The Sky's the Limit (1943).
A young and svelte John Banner plays Anton. Although Banner would become synonymous with his comic portrayal of Sgt. Schultz in Hogan's Heroes (1965), he was a classically trained actor from what was then Austria-Hungary. After Adolf Hitler's annexation of his homeland, Banner immigrated to America, where he served in the Army Air Corps during WW2. At the end of the war, he resumed his acting career in the U. S.
In an interview, Maureen O'Hara claimed John Garfield had to stand on a box in their close scenes because he was shorter than she.
Spending time on a ranch in Arizona at the time generally meant convalescing from illness or injury, both physical or emotional. McKittrick, just back from the Spanish Civil War, indicates both types of injuries early on when he's talking to his friend.