An athlete is killed and trepanned; Commander Carlos investigates, the assassin then kills a fighter; then the inspector proposes to the rancher Guillermo to pose as the vampire fighter to catch the killer who is Ogden, a scientist who wants to prolong human life by changing the brains of his victims for others of animals. He kills the rancher and takes his body to his laboratory, where he revives it with the brain of a gorilla; then it makes him fight; he defeats all his rivals, but when he takes off his mask his face has transformed into that of a gorilla and kills Ogden, and then looks for his girlfriend Lucia, the secretary of the arena, who is saved while the rancher dies. En México, el capitán de policía Carlos Robles (Crox Alvarado) no tiene pistas para resolver una serie de espeluznantes asesinatos de varios de los mejores atletas de México. Desconocido para el Comandante, el científico Don Panchito es responsable de los asesinatos y ha estado asesinando a la comunidad atlética con el fin de proporcionar sujetos de prueba para sus experimentos; El procedimiento de Panchito consiste en extirpar el cerebro de la víctima y reemplazarlo con el de un animal en un esfuerzo por encontrar una manera de conquistar la muerte.
