School days at St. Clare's are never boring for twins Pat and Isabel O'Sullivan in Enid Blyton's famous boarding school series. In the third book, Pat and Isabel eagerly anticipate their first summer term at St. Clare's. They soon become friends with the new girl Carlotta, who has a secret past she's desperately trying to hide. However, the cunning Prudence finds out and reveals it to everyone. How will the class react? There will be mischief at St. Clare's!

From 1941 to 1946, Enid Blyton wrote six novels set at St. Clare's. This edition contains the original text and is unread.