A mysterious stranger plays dueling families against each other in a Mexican border town.

During the lawless days that followed the death of Juarez, a lone American cowboy rides into the border town of San Miguel. He learns from the saloon proprietor, Silvanito, that the town is ruled by two rival, warring clans, the Rojos and the Baxters, both of whom have amassed fortunes by dealing in contraband whiskey and rifles. Quickly sensing the opportunity to make some money, the stranger picks a fight with four of the Baxters, shoots them, and then offers his high-priced services to the Rojos. Secretly and artfully he proceeds to intensify the disputes between the two families, constantly switching his allegiance as the bloody feud gains in intensity. He even arranges for Ramon Rojo's prisoner, the beautiful Marisol, to escape and be reunited with her husband and child. But this last act drives Ramon to a frenzy, and he has the stranger brutally tortured and maimed. Aided by Silvanito, the stranger escapes to an abandoned mine. Ramon, believing that the Baxters are harboring the fugitive, sets fire to their home and kills them all. For months the stranger nurses his wounds and perfects his shooting until he is ready for the final showdown. On that day he faces Ramon and the remaining Rojos, and he outdraws all of them. Then, hard-eyed and enigmatic, he rides out of San Miguel on a mule.