Thomas eventually comes to a stop next to the glittery gold shoes. He doesn’t do or say anything to attract attention. He stands and waits. Fake Jeanette, if she has noticed his arrival, shows no sign of it. Eventually one of the other two women nudges her and nods to indicate that Thomas is there.

Even now, there’s no communication at all between the two of them. Pretend Jeanette hugs one of the women good-bye, then sets off walking toward the Range Rover, trailing her arm out behind her and waving her hand as if to say, “Come on, this way.” Thomas follows her, but he hasn’t looked at her, not once, and nor has she looked at him. They haven’t spoken at all. It’s as if there’s no relationship between them, only indifference that goes both ways. The sole of Thomas’s damaged shoe continues to flop beneath his foot.

I duck down in my seat and cover my face with my hand, so as not to be seen as they pass me.

Not-Jeanette opens the back door of the car and Thomas climbs in. She closes it. Still, there has been no interaction or eye contact between them.

She’s going to drive away with him . . .

And now she has. And I did nothing.

Because there’s nothing you could have done.

Telling myself Thomas will be fine, I get out of the car and start to walk toward the school’s main entrance. Halfway there, I hear a voice calling my name.

I turn. At first I can’t see where it might have come from. Then I spot Lou, in the driver’s seat of a red Ford Fiesta. I didn’t see her leave the building; she must have come out while I was watching Thomas. She gestures toward me, and I see that the passenger door is open.

“Get in,” she mouths at me as I approach. She seems nervous, in a rush, as if we’ve just robbed a bank together and she’s driving the getaway car.

I obey the order. Another incentive to make sure we part on friendly terms—I’m going to need her to drop me back here later so that I can drive home.

Is it naive of me to trust her? What if she’s . . .

No. That’s paranoid. She’s a school receptionist. What’s she going to do—pull over and whip out a knife in broad daylight?

If someone wants me out of the way, presumably there are plenty of thugs for hire.

If Dom knew that I was even thinking in this way . . . “Where are we going?” I ask.

“The Gallery,” Lou says. “We can talk freely there.”

*

The Gallery turns out to be a crowded, homely café in Huntingdon, with square tables and a comforting smell of baked potatoes. Lou and I take the last available table. I tell her it’s my treat, whatever she wants to order, and thank her for being willing to talk to me, even though she’s the one who’s initiated the meeting.

“How did you get my number?” I ask her once we have our cups of tea in front of us. “My mobile phone, I mean. When you asked for my details, I gave you the landline.”

“You’ll think I’m a stalker.” She looks embarrassed. “I tried the landline and no one answered, so I googled you. I found your massage business Web site.”

With a photograph of me smiling, in my white work tunic, and both my phone numbers, mobile and landline, as well as my work email.

“Sorry,” says Lou unnecessarily.

“Don’t be. You’re no more of a stalker than we all are these days. You could have saved yourself the bother, though, and spoken to me yesterday.”

“I was too scared. I can’t believe I’m doing it now.” She shakes her head, as if at her own recklessness. “I could lose my job if I’m caught discussing families who are at the school. And I really need my job. My husband’s business had to fight an expensive legal battle last year that nearly cleaned us out.”

“That sounds rough. So . . . what changed your mind? About speaking to me. Was it the police?”

“Police?” Lou’s eyes widen.

“Or social services? Has someone been to the school today, or rung up, asking about the Caters?” It’s probably too soon. PC Paul Pollard might do something, but it will take him at least a day or two to get around to it. And the likelihood is, he’ll do nothing.

“No. Why would you think that?” Lou asks.

“I’m trying to work out why you suddenly decided you want to talk to me. Enough to look me up online and call me. That’s a big change from yesterday. Did something happen?”

Her eyes are flitting around, not settling anywhere. “Look, I need to know before this goes any further,” she says. “Are the police involved in whatever’s going on? Please tell me. Don’t lie.”

I try not to be irritated by the suggestion that I would. Something I can’t put my finger on makes me think that being completely straight with her is going to be the most effective strategy.

I take a long sip of my tea and start with my detour to Wyddial Lane last Saturday.

As simply and clearly as I can, I tell her everything. By the time I’ve finished, she’s drunk all her tea. My cup’s still full, and cold.

“And . . . you told all that to the police, everything you’ve just told me?”

I nod.

“Weren’t you embarrassed?”

“Why would I be?”

“It’s such a crazy-sounding story. It’s . . . I mean it’s outrageous.” She stresses the word. “I’m not saying I don’t believe you, but I couldn’t sit there and say all that to the police.”

“It’s not the first time I’ve been outrageous,” I tell her. “Sometimes you have to do the things no one else would do to get a result. My husband only got his first job because I applied for it on his behalf. Without telling him.”

“As his wife?”

“No. Pretending to be him.”

“Wow.”

I can’t tell if she’s impressed or repelled. “I’d shown him the advert and he’d said, ‘There’s no way I’d get that. I’m too inexperienced.’ And he was right, he wouldn’t have got it, because he’s not the sort of person who’d really sell himself in the bold way I could tell that particular company wanted. It was obvious from their ad. So I wrote an application letter basically saying ‘I’m brilliant and you won’t find better’—more subtly than that. It was a great letter, if I say so myself—witty, charming, but it made the point: ‘I’m the best you’ll get.’ And he got the job!”

“You’re very different from me,” says Lou. “I feel terrible for being here.”

“Then why are you?”

She stares into her empty teacup. I’m starting to feel the first prickle of impatience when she says, “If I talk to you about the Caters, will you swear never to tell anyone that the information came from me?”

“I can’t promise to tell nobody,” I say. “If the police do end up looking into it and they come back to me with—”

“I don’t mean the police. If there’s an official investigation, that’s different.”

“I promise that whatever you tell me won’t lead to you losing your job. You can trust me. I’m not going to land you in any trouble.”

She nods. “Yesterday, you asked me about Jeanette Cater’s accent, or your daughter did.”

I wait.

“Jeanette Cater—the woman I know by that name—has an English accent. Like yours.”

I show her the photo I took in the car park of the other woman. “Then who’s this?”

“Yanina. She’s the Caters’ nanny. I don’t know her last name. I think she’s Ukrainian.”

“And the woman you know as Jeanette—does she look a lot like Thomas, facially?”

“Yes. Oh! I might have a photo, from sports day.” Lou rummages in her bag. “I’m terrified I’ll lose my phone and then all my pictures’ll be gone. I’ve got hundreds on there. Should back them up, really.” When she pulls out her phone, a crumpled tissue and a hair clip fall out with it. She picks them up and stuffs them back in.

I sip my cold tea while she scrolls through her photos. “Here we are,” she says eventually. “This is Jeanette.” She passes the phone across the table to me.

It’s Flora. Her face is flushed and she’s wearing gray and blue running shoes, gray sweatpants and a red T-shirt. There are two women standing to her right, also wearing running gear. All three of them are smiling. Two of the smiles look natural and convincing. Flora’s is the odd one out: stiff and uncomfortable, as if it’s hurting her lips to make that shape.

“That was after the mums’ race.”

“This is Flora Braid,” I say.

“Are you sure?”

“Positive.”

“That’s so odd,” says Lou. “I wonder why she changed her name.”

Another peculiar aspect of this whole bizarre business has just struck me: many of the strangest details involve names. The Ukrainian nanny, Yanina, pretended her name was Jeanette. Either Flora’s doing the same in her dealings with her son’s school and her next-door neighbor, or else she really has changed her name to Jeanette Cater. And, since Thomas and Emily Braid can’t possibly have been frozen at the ages of five and three, then the Thomas and Emily I saw last Saturday in Hemingford Abbots must have been two different children—but their names are the same.

“It doesn’t surprise me that Mr. Cater and Yanina presented themselves to you as a married couple,” Lou says. “I’ve often thought they seem like more of a unit than Mr. and Mrs. Cater do. I’m not saying there’s anything going on between them. They’ve never shown signs of being romantically involved, but they seem to be . . . together, somehow. Like, a pair.”