Third Year at Malory Towers is a novel by Enid Blyton set in an English girls' boarding school.

Darrell excitedly talks about Malory Towers on the journey and is indignant when she discovers that Zerelda has fallen asleep.

When they arrive at the school, the other girls can hardly believe their eyes at the sight of Zerelda's makeup and startling hair styling.

On her first day the Fourth Form mistress, Miss Williams, initially mistakes her for a new member of the teaching staff.

Upon realising that Zerelda is a new girl, Miss Williams orders her to remove her makeup and rearrange her hair.

Wilhelmina, who has never attended school before, explains that she is always known as Bill and is looking forward to riding her horse Thunder every day, even if it means missing some lessons.

Thunder, her horse, is suffering from colic and Darrell, while searching for Mavis, discovers Bill in the stables tending to him.

In a thrilling end to the term, Darrell is picked for the school lacrosse team and shoots the winning goal.