Lefty Brown and Edward Johnson have spent 40 years working as cowboys in the old west. Edward's successful run for the senate ends their riding days, and Lefty is asked to run Edward's ranch and look after his wife, Laura. Laura worries that Lefty is not cut out for the job, but before he can show his worth Edward is shot and killed. Lefty immediately begins working to find the killer. Meanwhile, the main suspect in the murder is Lefty, and the Montana governor and a U.S. Marshal are hot on his trail.