The Spy Ring (1938)

Two American-army officers are working on a new type of machine-gun for anti-aircraft warfare, when one of them is murdered. The other vows to get the spies that are after the invention and avenge his friend's death.

Directed by: Joseph H. Lewis

Starring: William Hall, Jane Wyman, Esther Ralston, Robert Warwick, Leon Ames, Ben Alexander

Links: IMDb, Movie posters, Movie stills