Thomas Ward, the seventh son of a seventh son, is apprenticed to the local Spook - a kind of travelling exorcist specialising in ghosts, boggarts and witches. Against his master's orders, he befriends a young girl who turns out to be in league with a group of witches who kill babies and drink their blood. The rest of the story is concerned with his struggle to deal with the consequences of this fatal mistake. The style is simple and unadorned, the writing direct and immediate and the plot moves at a considerable pace. So it should appeal to young readers. But there's nothing very original in the treatment of the supernatural. Instead, the book derives its force almost entirely from its gruesomeness.