Fifth Formers of St Clare's: Book 8 by Enid Blyton

The O'Sullivan twins near the top of St Clare's

The last St Clare's book Enid Blyton wrote herself finds Pat and Isabel among the school's oldest girls, now expected to be dignified fifth-formers with studies of their own rather than dormitory pranksters. New arrivals bring fresh friction: musical Felicity Ray, self-important poet Anne-Marie, and Claudine's younger sister Antoinette, whose own brand of un-English mischief causes just as much chaos as her sister's once did. With a decision looming over who'll be made head girl, and classic Blyton lessons about vanity and kindness woven throughout, it's a satisfying penultimate instalment that closes out the series' main story arc.