The girls return to Malory Towers along with new girl, Ellen Wilson. A new head of form has to be elected, with Darrell, Alicia and Gwendoline all nominated for the position.
The new teacher, Mr. Parker finds that the girls behaviour in class is getting out of hand because of all the practical jokes and he decides to start using the humiliating dunce's cap.
The girl's efforts to make Ellen feel more included backfires. Ellen runs away to seek solace with a new friend she's found in the grounds. Darrell uncovers information that threatens the future of Malory Towers.
In an attempt to impress her parents, Gwen auditions for the lead role in the upcoming school play. But it doesn't go as well as she hoped. Meanwhile, Darrell and Sally try to work on a plan to save the school.
When Alicia's birthday hamper doesn't arrive from her parents, she sets out to have a bit of fun...until it backfires. Meanwhile, Gwen's lie about her father's sickness starts to spiral out of control.
Ellen is delighted to have finished the class test with time to spare, but it goes wrong. Anxious and upset, she disappears - the girls must find her. Meanwhile, Gwen is determined to get her hands on Darrell's diary.
When Miss Grayling invites a potential investor to the school, the girls must put on a day to impress. It's the day of Georgina's beloved play and Darrell is tasked to lead a tour - but all doesn't quite go to plan.
Whilst trapped in the San Gwen overhears news that threatens the existence of Malory Towers. Sally is left by Mam'zelle to take a lesson, but Alicia proves to be a tricky pupil.
Tensions come to a head between Darrell, Alicia and Sally when a sneezing trick is played on Mam'zelle. Meanwhile, Gwen is alarmed when Matron announces a trunk inspection.
The local boys school play Malory Towers in an inter-school quiz. Ellen's reputation is under threat when Darrell catches her sneaking around in the middle of the night.
The local boys school play Malory Towers in an inter-school quiz. Ellen's reputation is under threat when Darrell catches her sneaking around in the middle of the night.