I’m glad Alice and I have made up after our horrible row the night of the disco. We’ve both said sorry and we’re almost back to normal, although I don’t think either of us is ever going to forget about it.

“Where’s she going?” I ask.

“She’s meeting her boyfriend for lunch in Nando’s.”

“What’s he like?”

“Dunno. Never met him.”

“What’s he called?”

Alice shrugs. “Every time Dad or I ask her, she gets all cross and tells us to mind our own business.”

“Is that fake tan on her legs?”

“She’s had one of those professional sprays at the beauty salon.”

“Hope he’s worth it.”

Alice giggles. “Not if he’s taking her to Nando’s, he isn’t.”

“Do you think they have sex?”

Alice peers down the street. Catherine has now disappeared from sight. “Let’s go and look in her room and see if we can find any evidence.”

“What, you mean like check her sheets?”

Alice rolls her eyes. “No, of course not. She never brings him here. I mean contraceptives.”

We’ve just learned about contraceptives in Sex and Relationships at school.

It gives me an uncomfortable feeling, being in Catherine Dawson’s bedroom. If she changes her mind for some reason and comes back to the house and catches us in here, she’ll go ballistic. I’ll never forget that time she slapped Alice round the face. Such a vicious slap, too. Alice’s cheek was red for ages afterward. She tried to be brave and pretend it didn’t hurt, but it must have really stung. I’m sure if Alice had been on her own, Catherine wouldn’t have reacted half so badly. It was the fact that she’d sprayed the perfume onto my wrist that made her so angry. Why does she hate me so much?

Alice is already kneeling in front of her sister’s bedside cabinet and looking in the top drawer. I peer, nervously, over her shoulder. It’s really messy in there. Candy wrappers and lip-balm sticks; empty boxes of paracetamol; hair grips and scrunchies; emery boards and throat sweets. At least she won’t notice that the contents of the drawer have been disturbed.

At last, Alice pulls out a rectangular blister pack of white pills with days of the week printed under each one and little arrows indicating which order to take them in.

“Are these what I think they are?” she says, a note of glee in her voice.

I count the pills. “Twenty-one. Yes. She’s on the pill.”

“I wonder where they do it.”

“Perhaps he’s got a car.”

Alice giggles again. “We ought to follow her. See where they go.” She puts the pills back in the drawer and shuts it. “Shall we? We could spy on them in Nando’s.”

“But what if she sees us?”