Twelve-year-old Darrell Rivers is about to go to boarding school for the first time, and her new school is Malory Towers in Cornwall, which makes her even more excited. When she boards the school train, she notices that the two other new girls in her form and house are not easy to be friends with. There is Gwendoline Lacey, a spoiled only child who has never been to school before and only ever had a governess. The other new girl, Sally Hope, is unusually quiet and hardly speaks to anyone, and never talks about her home. This does not deter Darrell from making friends with the mischievous Alicia Johns and Betty Hill, her clever friend. This first term for Darrell is a hard one, for she first learns that if she joins in with Alicia's tricks in class she becomes behind in her work. Then when Gwendoline nearly drowns little Mary-Lou in the swimming-pool, Darrell slaps her and almost falls foul with the rest of her form. Whilst this school turmoil is happening, Darrell's mother writes to her, asking her to congratulate Sally about the birth of her little sister. Darrell does so, and Sally argues that she has no sister. At half-term, when Darrell's mother cannot find Sally, Darrell confronts Sally and pushes her to the floor in one of her violent rages. When Sally is sent to the sick-bay and becomes very ill, Darrell becomes worried and writes a letter to Sally's mother, explaining everything that she had done. However a wonderful surprise is in store, as she discovers that Sally had appendicitis and that her father (who is a surgeon) had treated her. After a long visit, Darrell and Sally become the best of friends, as she finds out that Sally had been jealous of her baby sister. Meanwhile, Gwendoline is still smarting from Darrell's slaps and is determined to get her revenge. She hides a large spider in Mary-Lou's desk and blames Darrell and Alicia for putting it there after it escapes during a French lesson. When this does not work, Gwendoline hatches a nastier plan by destroying Mary- Lou's pen and putting some inky shoes in Darrell's locker. Then it is up to Mary-Lou to find out who the real culprit is!
This synopsis report prepared by Liza Rosette