The Rivers Sisters return to Malory Towers where many changes abound. To begin with Darrell is now Head of Games, and Mary Lou is now Head of Lower Form. Meanwhile the second year form is joined by newcomer Josephine Jones, more commonly known as Jo. However Jo's father has raised her to be a rebel that attracts others, and when she befriends Felicity it is Felicity that has a hard time saying no and following the rules.

June takes drastic action to support Clarissa when a demanding Gwen pushes monitor duties too far - but will her radical plan pay off?

Josephine takes matters into her own hands when Miss Grayling denies the girls a trip to the circus. Keen to impress Felicity, Jo’s solution unleashes chaos at the school!

In a bid to prove that girls are just as good at football as boys, Felicity and June disguise Clarissa. Meanwhile, Darrell and Susan help Mr Murray with his chamber investigation.