Judith Fontaine (Regina Carrol) is looking for her sister, Joanie (Maria Lease), who has disappeared into the hippie community of Venice, California. It turns out that Joanie has become the victim of Groton (Lon Chaney Jr.), an ax-wielding homicidal maniac who is working for Dr. Durea (J. Carrol Naish), who is actually the last living member of the Frankenstein family and is now both running a house of horrors on the beach's boardwalk and performing experiments on Gorton's victims in his laboratory, down in the attraction's basement. One night, Count Dracula (Zandor Vorkov) visits the mad doctor, showing him the Frankenstein Monster (John Bloom), who was buried in a nearby graveyard. The doctor revives the Monster and uses him to take revenge on his professional rival, Dr. Beaumont (Forrest J Ackerman).