Two new girls have arrived at Malory Towers - and they couldn't be more different! Tomboy Bill spends more time with her horse than in the classroom, while American girl Zerelda seems determined not to fit in with the others.

Darrell has an exciting term in store. Not only does her sister Felicity start at Malory Towers, she's made Head of the Fourth Year! But can Darrell live up to the responsibility of the role?