Mario Prado

Legendary masked wrestler El Santo must stop a criminal gang.

Landru, a French businessman, arrives Mexico with the idea of ​​promoting their fighters, what nobody knows is that besides Landru promoter and fighter is a mad scientist who seeks to alter human genetics mixing it with the animal to make stronger and fiercer to their gladiators.

A wrestler is arrested on suspicion of assault, but his son manages to capture the real culprits.

Someone who wears a blue mask, is squat and has giant hands are killing people and stealing jewelry and money. The witnesses are afraid to talk, despite the detective understands that the clues point to his friend Blue Demon. This is actually an evil plan hatched by the Count and a fighter called ' The Cossack ', taking revenge on Blue. In both the real Blue Demon campaign starts with his secretary and a detective to unravel the mystery.