 U.S.Marshal "Rocky" Lane (Allan Lane) rides into the Black Hills country to help his old pal Nuggett Clark (Eddy Waller), whose freight business is almost bankrupt from bandit raids. Rocky finds a 16-year-old boy, Larry Stewart (Michael Hall), badly shaken from a fall down an embankment. His sullen attitude is explained when the Sheriff (Ed Cassidy as Edward Cassidy) arrives with a posse and tells Lane that the boy is a member of an outlaw gang, and takes him to jail. Lane persuades the sheriff to put the boy in his custody, and he takes him to the home of Nuggett and his niece, Sally (Leslye Banning.)The boy refuses to talk at first, but when outlaws Bart (Roy Barcroft) and Jake (John Cason) try to take him by force, and he learns that his brother Clay (Michael Barton) has been killed in cold blood by Bart, he tells Lane where the hideout is located. There,Lane finds evidence that the gang, unknown by Nugget, has been shipping gold by his freight line. Lane poses as an outlaw but Larry is unaware of the ruse and rushes to town to clear him, but confides in lawyer Gaines (John Vosper) who is the secret head of the outlaws. The gang takes Lane and Larry prisoner, steal the gold from Nugget s barn and take Sally as an hostage. Rocky and his horse Black Jack now have their work cut out for them.