While this series has not had the runaway success of Harry Potter, the books should be of interest to the same readers. The series started in 1975, considerably ahead of the Harry Potter series. It is about a young student at Miss Cackle's Academy for Witches. Mildred Hubble is a somewhat inept student, who counterbalances that with some amazing good luck. Her problems are complicated by her cat, Tabby, that is afraid of flying and also afraid of mice. This particular story has the students from her class off on an unexpected vacation at Gloom Castle.