“I don’t know. Well, actually I do know.” I laugh awkwardly. “Don’t worry too much—I mean, nothing’s happened yet, but . . . one of the dads from school has been following me. On Tuesday, he followed me all the way to London, where I used to live. Which means he must have followed me from my house to the train station and then on to a car-rental—”

“Whoa, whoa,” Kate silences me. “Which dad? Most of them wouldn’t have the gumption or the energy to follow the mother of another child. I’m almost impressed. Tell me everything, from the beginning.”

I do my best, aware of the inadequacy of my story. Until two days ago, I simply didn’t notice him apart from in the school parking lot. He might have been following me for months, or he might have only started on Tuesday.

The day after Damon Blundy was murdered.

I describe him as accurately as I can: the kind of clothes he wears, his car, the streaks in his hair. “I’ve always thought of him as Flash Dad,” I tell Kate.

“Can you describe his child or children?” she says quietly, after a short pause. “Let me answer that question for you: you can’t, can you? You’ve never seen him with his children.”

“No. Not that I’ve noticed. How did you know that?”

A longer pause. “You say you’ve noticed this guy a lot in the parking lot when you’ve dropped off and picked up your kids—going back a few months?”

“Yes. I can’t remember when I first noticed him, but . . . yes, certainly a month or two.”

“Have you ever seen him talking to any of the other parents?”

“No, but that’s not unusual for a school-gate dad,” I say. “It’s the mums that want to talk, generally. Lots of the dads keep their heads down and pray no one’ll put them out by forcing them to have a conversation. Look, just tell me who he is,” I blurt out.

“I’ve no idea who he is,” Kate says.

“Then how did you know I’d never seen his kids? Why do you sound so worried, as if you’ve worked something out and you’re wondering whether you should tell me or not? You should. This man followed me to London, to my brother’s house!”

“OK, don’t freak out. You will, but don’t. The guy you described isn’t a parent at Freeth Lane. I know every parent—more’s the pity—and there’s no dad with streaked hair and a blue Beemer. And before you ask, no, there are no mothers’ boyfriends, male nannies . . . There’s no one I can think of who fits that description, Nicki. No one associated with Freeth Lane.” Kate sighs. “Which means . . . well, I’m sure I don’t have to tell you.”