When his son is killed by Big Henry, the bandit El Toro receives a note from Dolores saying his grandson is in danger. Setting out to retrieve him, he saves Hoppy's life. Hoppy then takes over the task knowing lawmen are looking for El Toro. Hoppy finds Dolores only to see her killed by Big Henry. Johhny then uses the mud on Dolores' boots to find the boy. But he was followed and Big Henry, now on to Hoppy's game and knowing the boy's location, sends Hoppy into a trap.

A group of bandits led by Big Henry kills the son and daughter-in-law of Señor Chavez, as they are carrying gold across the Mexican border to Chavez. His grandson Pablo witnessed the murders and is rescued by Henry's girl friend Dolores, a dancer in Henry's saloon. Dolores is about to ask Henry to take Pablo home but realizes he is the murderer and sends word to Señor Chavez to meet her at Henry's El Infierno Bar. When sheriff Bill Cassidy discovers El Toro, a notorious Mexican bandit, is in town, he and deputy Johnny Nelson go after him. While in pursuit, Bill gets trapped in quicksand and is saved by El Toro. As Bill is about to arrest El Toro, he reveals himself as Señor Chavez, and moved by his plight, Bill promises to save Pablo. In Henry's saloon, Dolores is about to reveal Pablo's hiding place to Bill when Henry realizes her duplicity and kills her, claiming she has committed suicide. At the bar, Bill shoots Henry's partner, Ed, as he threatens to kill old bartender Spike. Impressed with Bill, Henry invites him to join his gang. Jealous gang member Mike goes after Bill in order to avenge Ed's death, but dies when his horse drags him. Johnny, meanwhile, discovers red clay on Dolores' boots, and Spike advises him to go to Red Mountain. Steve, another of Henry's men, follows and wounds Johnny after overhearing him explain El Toro's wishes to Bill. Steve reports Bill's duplicity to Henry, who sends Steve and Bill to retrieve Mike's body, then follows with Spike and a posse. Spike is killed while trying to warn Bill that Johnny has been wounded. Bill shoots down the posse then races to Red Mountain and saves Pablo just as Henry arrives. Henry and Bill fight and Henry falls to his death. Bill and Johnny then return Pablo to Señor Chavez.