Felicity is Head Girl of Malory Towers! Eager to prove herself, she has her hands full with naughty first formers, and a very mysterious new form-mate who is strangely familiar.

After taking their Higher Certificate, the sixth formers want to relax this term. But the Head has a surprise: a finishing school course, with old girl Gwendoline Lacey as teacher. Yet someone is determined to drive her out - and it takes the return of Darrell to solve the mystery.

New girl Millicent clashes with the feisty June over the school's priorities: a music concert or tennis tournament? But both pale into insignificance when it's found there's a thief in the fifth form.

Darrell has left, and Felicity is head of the third form. And what a lot she has to deal with - June and new girl Freddie playing tricks continually, the sickly Bonnie shadowing her, and the stuck-up Amy, who has a strange family secret.

Susan is excited to be in charge of the winter concert, but Miss Tallant, a new teacher, has very strong ideas about it. And when she interferes in a midnight feast, they realise there's a spy in their midst. But who could it be?

There's a mystery at the nearby stables - someone has stolen money and then poor Julie's horse. Can the third form help old girls Bill and Clarissa discover who is behind it?

The O'Sullivan twins are head girls! There's two cheeky first formers - more twins! - and a sulky new girl in the sixth form, Morag. Morag detests St Clare's. She's only happy when she can escape to the local riding stables. The twins are sad it's their last year at St Clare's. Before they leave, will they find out what's wrong with Morag?

Kitty Flaherty is joining St Clare's, along with McGinty the goat! The girls know that this term is going to be full of fun. But it's also full of upset. Pat misses the first few weeks, thanks to a broken arm, and another new girl, Amanda, seizes the opportunity to become Isabel's new best friend. Will the twins overcome this rift?