 In this entry of Monogram s "Rough Riders" series (no relationship to the dull TV series of the 50 s), Ma Turner (Sarah Padden) of Red Bluff sends for U.S.Marshal Buck Roberts (Buck Jones) to investigate a series of wide-spread rustling in the area. Town banker Miller (Walter McGrail), saloon-owner Duke Mason (Harry Woods) and the crooked sheriff (Lee Phelps) are in cahoots with rancher John Holt, but they double-cross and kill him. His son Steve (Dennis Moore) witnesses the murder and kills the sheriff. Buck arrives and arrests Steve. Marshal Tim McCall (Tim McCoy), posing as an outlaw, gains the confidence of the gang and engineers the escape, with Buck s knowledge, of Steve from the jail. Sandy Hopkins (Raymond Hatton), the third Marshal of the trio, poses as a peddler and learns that the gang intends to do away with Buck and rides to the Turner ranch to warn him. Red (Bud Osborne), a Turner ranch hand but also a member of the gang, overhears Buck telling Ma that Tim is really a U.S. Marshal, and he has Miller and Mason informed.