Stewart Larsen's son, Bud, is killed by Chet Ogden, foreman of El Cajón Rancho and veterinarian of the Cattlemen's Association, who has falsely told Larsen that his cattle were infected. Ogden plans to sell the cattle in Mexico. Larsen blames Don Felipe Ortega, owner of El Cajón and president of the association, and swears vengeance. Years later, Larsen, now known as "The Son of the Wolf," menaces the countryside with his gang. His foster son, Jim, is wounded and captured by Ortega and is nursed back to health by Ortega's daughter, Ynez. Hearing a report that Jim is turning traitor, Larsen goes after Ortega, but Jim prevents Larsen from killing him. Jim and Larsen attempt to escape, but Larsen is fatally wounded by Ogden. Jim chases Ogden, who falls to his death during a fight. Ogden's accomplice, Hippy Jake, confesses to the dying Larsen Ogden's guilt in starting the feud. Larsen dies, and all parties are reconciled.