It's New Year's Eve at the Villa Nightmare but Beelzebub Preposteror is in no mood for celebration. As the Shadow Sorcery Minister, Preposteror has a duty to perform a certain number of evil deeds in service to the Minister of Pitch Darkness. But this year, to his horror, he's nowhere near meeting that quota. Preposteror has all but given up when who should make an unexpected visit but his aunt, the witch Tyrannia Vampirella. She has come with a diabolical proposal that just might be the solution to Preposterer's dilemma: together they will brew the fabled Notion Potion, "one of the most ancient and powerful evil spells in the universe," and their every evil wish will be granted.

The only thing that stands in their way is a most unlikely team--a cat named Mauricio di Mauro and a raven known as Jacob Scribble, who have just hours to thwart the plans of their sorcerer masters and save the world from destruction.