Frame Johnson (Walter Huston) is an itinerant gambler traveling among frontier towns with three companions. Arriving in Tombstone, they discover a corrupt outpost dominated by Poe Northrup (Ralph Ince) and his vicious brothers. Frame is recognized as the renowned former lawman "Saint" Johnson, but does not wish to get involved. After the Northrups push him too far, though, he accepts the job of town marshal. Conflict comes to a head with a climactic gunfight at the OK Corral.