The girls are excited about a special weekend trip to Witch World theme park but the treat is cancelled when Miss Cackle appears to have fallen victim to the dreaded Witch Fever and the school is put into quarantine. All the girls are disappointed but Hettie is devastated, not least because everyone seems to think she is somehow to blame for letting the disease out into the school. With Miss Cackle in the Sick Bay, Miss Hardbroom is secretly relishing being in total control of the school and institutes a programme of organised weekend activities, which must be undertaken in silence. The special weekend has turned into a nightmare and everyone knows who to blame. But Hettie, as ever, has a plan...