Reckless gambler Tim Donovan pursues the gang that has just held up the Black Mountain stage. He retrieves the strongbox, but the robbers escape. Bumbling Sheriff Clay Matthews finds Donovan with the loot and arrests him. He is set free by Judge Harper, who knows that Donovan is actually a U.S. Marshal sent undercover to investigate the gang who has been terrorizing the stage line. Donovan discovers a conspiracy involving a bank president and an officer of the stagecoach company. Tim will need to turn upevidence fast, before the criminals are allowed to escape.Tim McCoy was a western superstar in the '20s and '30s, appearing in scores of early films for MGM and smaller studios. A bona fide cowboy, he was an expert horseman, roper and a sharpshooter. After serving as an officer in World War II he returned to Hollywood to star in The Rough Riders film series with Buck Jones and Raymond Hatton.