Loner U.S. Marshal John Travers (John Wayne) foils the hold-up of a stagecoach, rescuing young woman Anita Matlock (Verna Hillie) from the clutches of the crooks and helping her back to town. But there, the sheriff is gunned down by bandits, so Travers starts investigating and connects the murder to a gang, led by an unidentified bandit known as the Shadow, who's been running the town ragged for some time. Travers then makes it his mission to restore order to the town and bring down the Shadow.