Buffalo hunter Matt Fletcher enters a church in the border town of Ojo Prieto.  He plans to begin a new life by using his magnificent Appaloosa stallion to start a horse breeding farm with his old friend Paco, an impoverished Mexican farmer.  His hopes are ruined, however, when Trini, a young woman who has been sold by her parents to Mexican bandit Chuy Medina, tells Chuy that Matt molested her in church.  When Chuy enters the church, Trini escapes on Matt's Appaloosa, but she is quickly captured and returned by Chuy's pistoleros.  Matt's hopes are shattered when Chuy steals the horse and drags Matt by a rope through a rock-strewn brook.

After recovering from his injuries, Matt ventures into Chuy's stronghold and confronts him in a hand-wrestling match in which poisonous scorpions await the one whose arm is forced to the table.  Matt loses but saves his life by cutting open the wound with a piece of broken glass.  Trini comes to his aid and hides him in a shack owned by Ramos, a goatherd, and nurses him back to health.

Squint-Eye, another of Chuy's pistoleros, comes to the shack looking for Matt and Trini, and when Ramos refuses to divulge their whereabouts, Squint-Eye kills Ramos.  After killing Squint-Eye, Matt then returns to Chuy's stronghold, retrieves the Appaloosa, and flees toward the border with Trini.  Chuy follows, and Matt, realizing that Trini means more to him than the horse, sends out the Appaloosa to draw Chuy's fire.  As the bandit aims for the horse, Matt fires and kills him. Matt and Trini then cross the border with the Appaloosa to start a new life.