Mean Girls by Lesley Whyte

Apparently not every school has a clique problem, but ours did. Ours really did. And it wasn't the cheerleaders, as you might expect, if you've ever watched a movie or TV show or - God forbid - read a book that's aimed at teenage girls. We're taught to expect the cheerleaders to be bitches. To torment the clever, the plain, the unworthy. Our cheerleaders were actually pretty nice. If they found time to speak to you, of course. They were serious about their sport. For them, it really was even more than that. They were driven and focused and just didn't have time to waste on ruining other people's lives.

No, it was the pretty, apathetic girls you wanted to watch out for. The bored, spoiled ones who had no hobbies and interests except for making other people miserable. And they were very, very good at it. The worst was Tyler Prince. She was terrifying. People were scared to speak in front of her, afraid that it would somehow come back to haunt them. She was beautiful and terrifying.

She and her friends did all the usual things - spreading rumours, hiding clothes, stealing textbooks, sending fake emails, writing words like SLUT or WHORE on lockers in bright red lipstick. You know, the usual. But then, occasionally, they'd go just that bit further. They'd work their little brains up in a frenzy, the smell of smoke following them for days, and come up with something a bit more creative.

I think the worst thing they ever did was the fortune cookies. I still don't know how they managed it. It was decided that the entire junior class would have Chinese food on the last day before summer break, I suppose Tyler and her friends decided that, seeing as she was class president - a role that required really very little of her. We ate our shrimp lo mein and sweet and sour chicken balls, and then the fortune cookies came around. All the girls had...shall we say, personalised messages.

And not friendly ones. 

Mine said You're worthless and always will be. Why bother?

I still don't know how they managed it.