A bunch of angry lepers escape an institution, turn into outlaws, raid a town, and attract the attention of some local badmen who want to team up with them to wreak havoc. Enter a good hombre with a silver mask: El Santo, who shall restore peace.

Cowboys, step aside. Santo has come to the rescue in the Wild West! In this surprisingly straight-laced outing for the masked hero, director René Cardona brilliantly subverts Hollywood stereotypes of Mexican characters, lending a local flavor to the well-worn tropes of classic frontier tales.