Belinda Morris - Irene's best friend and equally scatterbrained friend, a talented artist.Irene - a scatterbrained girl who excels at music and mathematics.

Zerelda Brass - a new girl, from the United States.Wilhelmina (Bill) Robinson - a new girl, obsessed with horses and particularly her own horse, 'Thunder'.Mary-Lou - now a little taller, but still timid and 'scared looking'.Jean MacDonald - shrewd Scottish girl, honest and dependable, now Head Girl of the Third Form.Alicia Johns - lively and quick-witted, always ready with an sharp-tongued opinion.Gwendoline Mary Lacey - spoiled, lazy, boastful and conceited.Sally Hope - Darrell's best friend, solid and dependable.Darrell Rivers - the main protagonist of the stories.The end of term comes and the girls can't wait to see their parents again. Ms Peters saves the day and she and Bill become very close friends. A few weeks later, Thunder (Bill's horse) suffers from colic while Darrell and Bill work all night in the rain to stop him lying down and Ms Peters rides for miles in the pouring rain to get the vet and saves the life of aspiring opera singer Mavis Allyson who loses her voice as a consequence. Later, drama teacher Ms Hibbert tells her she is unable to act. When Zerelda tries to rehearse for the third form play, 'Romeo & Juliet' and is caught throwing a book at a former classmate, she is scolded by Matron. Darrell becomes a reserve for one of the Malory Towers lacrosse teams. A few weeks later, Zerelda is demoted to the third form because her standard is lower than the fourth form's requirement. The brothers and their horses leave leaving Bill to take her horse, Thunder, to the stables. She arrives with the brothers and her horse. Bill is short for Wilhelmina, who in turn has truckloads of horses and seven brothers. A few days later, the final new girl arrives Bill Robinson. It is then revealed that not only is Zerelda in North Tower but in the fourth form.

Alicia notices it and points it out to Darrell. When Gwendoline sees Zerelda, she immediately loses her heart to her. Once they arrive, they see Gwendoline making a Fond Farewell with her mother and governess. On the way, they pick up a new girl, Zerelda Brass, who is fifteen and a half and from the US. She finds out that Sally Hope, her best friend is in quarantine for mumps and will not be able to come to school for a short time. Darrell is on the way to Malory Towers once again.

Third term at malory towers