This is the story of an eventful term: 2nd years Anna and Denise want to make money and have adventures to write up on the blog they're creating. They set up an above-board business running children's parties and a covert vigilante business - meting out other people's revenge (e.g. hiding gymbags, spoiling homework). They defend their actions by claiming that they're fighting injustice. Both explore the other sex - Anna is practical and sets herself up with boyfriends, Denise is romantic and dreams about boys. They are self-absorbed and wrapped up in each other and don't notice the real injustice under their noses: Denise is ignoring her younger sister, Justine, who is suffering. The book relates how they finally use their undoubted ingenuity for a good cause - saving Justine - and how they lose some of their self-absorption and widen their friendship to include others.