Two Italian newlyweds, Camillo Fumagalli and Adelaide Ferretti, on their honeymoon in England cannot find accommodation and, due to the fog, end up lost in the countryside in sight of an ancient castle, where they ask to stay overnight.
Here the spirit of the ancient baron of Black Castle, unrepentant womanizer in life, assisted by his faithful Angus - who boasts his own apprenticeship with Frankenstein - through potions, sleeping pills and various devilry, takes the place of the naive new husband with the unsuspecting bride, continuing, as a ghost, the adventures of his past as a libertine, until he is in turn duped by Angus and relocated in the portrait gallery of his ancestors.