Sent to Groosham Grange by his parents, David Eliot quickly discovers that his new school is a very odd place indeed. New pupils are made to sign their names in blood; the French teacher disappears every full moon; and the assistant headmaster keeps something very chilling in his room.
Charlie's Uncle Paton has dashed off to try to stop the Yewbeam aunts' latest plan, but when Grandma Bone greets the arrival of Belle with delight, could this be what Paton left hoping to prevent?