Billy Bucklin escapes while being transported to Yuma prison and plans to form an army of desperadoes to control the Mexican border. To finance his band, he robs a stagecoach, kidnaps a beautiful woman to be sold into prostitution, and steals an army payroll wagon. An aging lawman persuades the governor to parole his brother-in-law, now serving a 20-year prison term for murder, to assist him and his green deputy to destroy the marauders.