The Mystery Man.

Hard-boiled newspaper reporter Larry Doyle (Robert Armstrong) goes a bit too far in celebrating a work bonus and wakes up on a train bound for St. Louis with only a buck on his person. To remedy the problem, Doyle pawns the revolver he's carrying. When the gun is subsequently used in a murder, Doyle's problems only multiply. In the meantime, he's also fallen in love with a comely stranger (Maxine Doyle) he convinced to impersonate his wife.