 Don Pedro Madera (Francis Ford) drives his sister from the Madera rancho because he is displeased she has married a gringo. Sister and gringo have a son Juan (Ken Maynard) who, years later when he is grown, is seeking revenge, as the bandit El Lobo against Madera. The latter does not know that El Lobo/Juan is his nephew. As Juan, he saves the life of Anita (Doris Hill), whose hand is promised to Jose Madera (Gino Corrado), but she is attracted to Juan and he is invited to a fiesta at the rancho. There, he is recognized as the bandit El Lobo by Conchita (Joyzelle), a girl who gets around. Some of her getting around includes being caught in the arms of Jose the cad, and this leads to Madera learing that Juan is really his nephew, Jose being a whole lot discredited and Madera blessing a marriage between Juan and Anita.