De tornada a l'ancestral castell 25 anys després de la mort del monstre, el fill del doctor Frankenstein coneix a Ygor, un pastor boig que amaga la terrible criatura. Buscant netejar el nom de la família, reviu el monstre i ho intenta rehabilitar.
Dramatisation of the true story of the notorious 'acid bath murderer' John Haigh, who murdered women and disposed of their bodies in vats of acid in the 1940s. He was only caught when the gallstones of one of his victims failed to dissolve in the acid and were detected by the pathologist who examined the residue from the acid bath.