She hands me my packed lunch and watches me stuff it into my rucksack. Then she kisses me goodbye and the feeling of unease that’s been fluttering away inside my belly ever since I woke up swells and swells till I think I’m going to be sick. Suddenly, the prospect of a day out at a sewage plant doesn’t seem quite as bad as what Alice and I have planned, but I can’t wriggle out of it now. Alice will be cross and I don’t think I can bear it if we start arguing again.

Sometimes, I wonder whether it’s only a matter of time before Alice drifts away from me and starts hanging around with Melissa and Bethany instead. I’ve seen her gaze over at them in the classroom from time to time, as if she wishes she were sitting with them, a proper, paid-up member of the cool girls’ gang.

My bus is packed when it pulls up, and I squeeze down the middle and cling on to the pole near the doors. A boy near me is eating Cheesy Wotsits and what with the smell of them and the coating of orange dust on his mouth and fingers, which, for some reason, I can’t stop looking at, even though I don’t want to, and the continual stopping and starting of the bus, it’s a wonder I don’t throw up.

At last, it’s time to get off and, as planned, Alice is there at the bus stop, waiting for me.

“All set for the trip?” she says, a mischievous gleam in her eyes. It’s all right for her. She’s not the one who has to make a fool of herself.

I nod. The closer we get to school, the more nervous I get. My armpits are already wet with sweat and I’m embarrassed about the spreading stains on my school blouse. I want to get this over with as fast as possible.

We slow down till the big group of chattering Year Sevens overtakes us, and that’s when Alice gives me the sign we’ve agreed on. She pauses to retie her shoelace and I start to stagger around for a bit, pretend to fall over, which is a lot harder than I ever imagined. I should have practiced more in my bedroom. I did try, but I didn’t want Mum and Dad to hear me crashing around and come rushing in to see if I was all right.