When Baby B the beaver and Nick the hedgehog bring Philip a message that he is needed back at Beaver Towers, which he had helped to free from the witch Oyin, he returns only a step ahead of Oyin's master, the Prince of Darkness.
While playing Indians in Little Thicket, a group of English schoolchildren who call themselves the Secret Seven spot the thief who stole Lady Lucy Thomas's valuable pearl necklace, and they determine to find where he hid the jewelry.
Horrid Henry tries to convince the Tooth Fairy to come when he has not lost a tooth, takes part in his cousin's wedding, has Moody Margaret as his guest, and bets he will make the new substitute run screaming out of class by lunch.
Delilah is appalled. Edward, her owner, has gone on holiday without her. so Delilah decides to leave home. But the grim city is no place for a proud beautiful cat.
When an anonymous note claims someone in the class is a witch, everyone is eager to prove it is someone else, and Chrestomanci arrives just in time to prevent disaster.