A renowned gunslinger with a storied past, Tom Horn (Steve McQueen) opts for a reclusive life until he starts working for rancher John Coble (Richard Farnsworth). Though Horn begins seeing pretty local teacher Glendolene Kimmel (Linda Evans), he remains restless. Investigating livestock theft, Horn is brutal when dealing with criminals, and while his presence is initially appreciated, eventually the community grows concerned about the enforcer's violent methods.