Adam Stewart, a lawyer heading west with grown son Howie, is persuaded by brother John to settle down near him in Ocatilla, Arizona, where he has a ranch and romantic interest in a widow, Corinne Michaels.
The menacing degenerate rancher Wick Campbell has an attractive servant girl, Maria Segura, and also lusts for her, but she wants nothing to do with him. Her interest in Howie strikes a jealous chord in Campbell, who hires gunfighters led by Frank Scavo to rid the region of the meddlesome (in his opinion) Stewarts once and for all.
Campbell's thugs kill a rancher and stampede some of John Stewart's cattle. One picks a fight with Howie, who surprisingly beats him to the draw in self-defense, only to be locked up by Sheriff Gibbons, falsely accused of murder. Howie busts out and flees with Maria.
Adam Stewart is killed in cold blood by Campbell, for which Howie blames himself while promising to get even. John Stewart goes into town to confront Campbell but can't find him. He's lured into a gunfight with one of Campbell's men and kills him. He escapes to Corinne's home, where he and other town leaders are trapped by Campbell's men who put the house under siege. Scavo gets hold of dynamite and begins blowing the house apart room by room. Two of the men in the house are killed, but John and Howie escape to a nearby river. Scavo throws sticks of dynamite into the river, thinking he's killed them both,
Scavo turns on Campbell, takes his gun, makes him give him the money from his safe, and says that he is now running things. Campbell goes to Maria to persuade her to come with him but is confronted by John, who has been hiding at Maria's house with a wounded Howie, and is killed in a gunfight.
John rides to town to take on Scavo's men and prevails. The city has law and order, while the Stewarts celebrate a double wedding with John marrying Corrine and Howie marrying Maria.
