FLY BY NIGHT was made in 1942, shortly after the USA had joined WWII, and you keep getting messages about buying goods to support the war effort. That said, the action in the movie is as far removed from the war as a mouse from a cat.
Director Siodmak does a good job of keeping the action ticking despite a script that, for the first third, struck me as a clear rip-off of Alfred Hitckcock's THE 39 STEPS (UK 1935), and that includes surprisingly pleasant touches of humor, especially as the couple pretend to be married and see circumstances force them into marriage.
Carlson and Kelly make a handsome and likable leading duo, aided by a good if largely unknown support cast. Photography is of an acceptable standard.
This B pic deserves watching - short, breezy, sweet, no waste of time!