Ne'er-do-well Tom Newcombe is publicly hanged for murdering a woman because the local school teacher, Celia Ames (Colleen Dewhurst), refuses to alibi him. A mysterious man, Paul Taylor (Hugh O'Brien), comes to town, signs on to work as a Shiloh Ranch hand and begins romancing Celia. However, his odd behaviour begins to raise the suspicions of Judge Garth and the local Sheriff who wonder about the motives of the stranger.

Columbian Enrique Cuellar (Ricardo Montalban) has inherited land which was leased and used by Judge Garth. The Judge wants to renew the lease or buy the land outright. He minimizes its importance to his operations even though it contains a pass needed to drive his cattle herd between its seasonal ranges. Enrique discovers this deception and demands a large amount of money for the land. The Judge decides to drive his cattle through the land before Enrique can get a legal restraining order and in turn Enrique begins erecting a barbed wire fence to block the passage. A violent confrontation seems inevitable but is prevented by an unpredictable event involving Betsy Garth.