This movie is the first of a trilogy that Sebastián D'Arbó, a specialist in parapsychology, filmed on occult topics. The second film is El ser (1982) and the last one Más allá de la muerte (1986).
A group of international criminals steal a large emerald from a heavily guarded Colombian mine and they plan to sell it on the black market. Unfortunately, the evil Dr. Igor is also manipulating other criminals, as well as the ones who stole the emerald, for his own benefit. Santo, a Mexican wrestler/Interpol agent works with the Colombian authorities in an attempt to recover the emerald and to stop Dr. Igor and his subordinates, as well.
Luis, the son of the greater of the farm owned by Don Pedro, is accused of stealing a large amount of money. Stolen money has really Joseph son of Don Pedro, forcing Louis to confess to the robbery, threatening to take the farm to his parents, older may not work elsewhere. With this move, Joseph not only is cleared of any suspicion but also with a clear path to reach dew, until then girlfriend of Luis.
