Rufus attends his first Samhain celebration with his mother, grandmother and Aunt Ruth. He finds the evening boring and wishes he'd gone Trick or Treating with Billy and his other friends. When the entire circle of witches is outside watching a display of fireworks, a witch appears in the night's sky and puts on a show of magic that outdoes the fireworks. This is Rufus's evil uncle Hector, his father's brother, whom Rufus has never met. Later that evening, Uncle Hector shows up outside Rufus's room and takes him for a magical ride. He tells Rufus he has decided to make him his heir apparent.

Though he's been warned to have nothing to do with Uncle Hector, Rufus makes secret visits to his uncle's amazing estate that includes a stable of horses and a small zoo. Hector tells Rufus that everything he owns-his many businesses and enterprises-will eventually belong to him. Hector teaches him powerful spells his mother would never teach him.

Rufus is bedazzled by his uncle's wealth and power, but he's beginning to notice Hector's occasional cruel behavior toward innocent parties. Finally, Hector orders Rufus to do something bad, something Rufus refuses to do. Hector warns Rufus not to ask anyone in his family for help or there will be dire consequences. Sure enough, Hector stirs up trouble in a way Rufus has never imagined.

What can Rufus do to stop his evil uncle, once and for all, from bringing harm and danger to the people he loves?