Tom Logan is a horse thief. Rancher David Braxton has horses, and a daughter, worth stealing. But Braxton has just hired Lee Clayton, an infamous "regulator", to hunt down the horse thieves; one at a time. 美国初期的拓荒时代，西部边境一片广土众民，以求在西部安身立命，这批移民之中以已命徒为最多，粗旷的山谷与莽汉恰成一格。汤姆洛根家道中落，遂与三位朋友前往西部，企图以抢劫火车、银行的方式凑钱买块农场，然后洗心革面重新做人，无奈刚抵西部，其中一人就因偷马而被当地富绅问吊，该富绅并请来身手不凡的法务……
