When a teacher at an English boarding school finds a note on his desk accusing someone in the class of being a witch, magical things begin to happen and an Inquisitor is summoned.
Lynn Morley and Mouse spot strange purple weeds growing exactly where they threw old Mrs. Tuggle's glass eye in The Witch's Eye. Could these ominous plants be witch weeds?
When an anonymous note claims someone in the class is a witch, everyone is eager to prove it is someone else, and Chrestomancy arrives just in time to prevent disaster