Cougar et sa bande de pillards traversent le Rio Grande et effectuent un raid meurtrier dans lequel est tué Bob Houston, le frère de Jim. Celui-ci franchit à son tour la frontière en se faisant passer pour un tueur recherché, en espérant pouvoir attirer Cougar au Texas ou l'attendent les Rangers.

The Buck Jones western The Fighting Ranger utilizes its familiar plotline with excellent results. When Jones' kid brother is killed by the villains, our hero quits the Texas Rangers and sets off to seek vengeance on his own. He ends up just below the Mexican border, where bandit leader Cougar (Bradley Page) lives high off the hog, knowing he can't be extradited.