Hanna Frankenstein, disappointed in her nephew's antics, decides to restore the Frankenstein name by sprucing up the castle. The task gets easier when she finds something from the cellar, but the villagers become increasingly alarmed when they start seeing signs of activity in the crumbled castle. Can Aunt Frankenstein really make up for her nephew's past mistakes?

Monster mashes can sometimes be problematic, because introducing several classic horror characters in one story can seem overwhelming. Pettersson keeps it fairly well together, though, and the characters don't come across as glued on despite not having that much use in the story overall. The lack of a major plot, where each of the character would have a more sensible part, is the one weakness of Frankenstein's Aunt.

However, Pettersson's vivid use of language and sense of humour are a delight, the latter which is most evident in the suggestive scene between Aunt Frankenstein and Dracula. Dracula would rather stand because of his circulation, and Aunt comments how she's the type of old lady who doesn't have much money in the bank. Dracula's bloody toy boy aspirations quickly come to an end, though.

Frankenstein's Aunt is the type of novel I imagine wouldn't be published today, and not just because of Aunt's addiction to cigars and sherry. It's easy to make monsters caricatures in novels aimed at a young audience. Pettersson avoids that trap and doesn't treat the monsters like clichés, but comes up with something at least a little bit new for each without them coming across like out of character. Like in the very best monster mashes, it's enjoyable to see the creatures interacting. The Fearless Vampire Killers ending is pretty great as well.