When Melissa (Agnés Spaak) returns to her ancestral home to claim her inheritance, she finds that the castle is filled with strange characters and dark secrets. Governing the crumbling manor is a diabolical scientist, Dr. Conrad Jekyll (Marcelo Arroita-Jáuregui), who uses high-frequency mind control to command an undead henchman (Hugo Blanco) to perform a series of vicious murders. When a dry-witted detective (Pastor Serrador) and Melissa's suitor (Pepe Rubio) trace the crimes back to Jekyll's castle, they realize the only way to trap the zombie is to use Melissa as bait.