Old timer Hank Robbins and his young pal,"Red" Hepner ride into the town of Cajon, Mexico and find it under a reign of terror imposed by a mysterious outlaw known as El Lobo. Don Jose Valencia is also upset over the romance between his son Francisco and saloon girl Dolores. Pete Sangor, an American resident, has his eye on the girl also. "Red" and Hank discover that Sangor is El Lobo, and ride to rescue the kidnapped Francisco.