In Enid Blyton's bestselling school series Elizabeth Allen is sent away to boarding school and makes up her mind to be the naughtiest pupil there's ever been. In book five, Elizabeth intends never to be naughty again.

But when John entrusts her with his secret, the naughtiest girl finds herself in deeper trouble than ever ... Between 1940 and 1952, Enid Blyton wrote four novels about Naughtiest Girl, Elizabeth Allen.

Books 5-10 are authorised sequels of the series written by Anne Digby in 1999.

Both cover and inside illustrations were created by Kate Hindley in 2014.

Bonus material: A rare, complete serial story about a very special school. An interview with Enid Blyton about her school days. Enid Blyton's experiences as a teacher. A timeline of the author's life. Photos from Enid Blyton's younger days.