OK. A fake ring is a bad idea. There are a million reasons why. Such as:

1. It’s dishonest.

2. It probably won’t look convincing.

3. It’s unethical.50

Nevertheless, here I am at Hatton Garden at ten the following morning, sauntering along, trying to hide the fact that my eyes are on stalks. I’ve never been to Hatton Garden before; I didn’t even know it existed. A whole street of jewelers?

There are more diamonds here than I’ve seen in my lifetime. Signs everywhere are boasting best prices, highest carats, superb value, and bespoke design. Obviously this is engagement ring city. Couples are wandering along and girls are pointing through the windows and the men are smiling but all look slightly sick whenever their girlfriends turn away.

I’ve never even been into a jewelry shop. Not a grown-up, proper one like these. The only jewelry I’ve ever had has come from markets and Topshop, places like that. My parents gave me a pair of pearl studs for my thirteenth birthday, but I didn’t go into the shop with them. Jewelry shops have been places I’ve walked past, thinking they’re for other people. But now, since I’m here, I can’t help having a good old look.

Who would buy a brooch made out of yellow diamonds in the shape of a spider for £12,500? It’s a mystery to me, like who buys those revolting sofas with swirly arms they advertise on the telly.

Sam’s friend’s shop is called Mark Spencer Designs and thankfully doesn’t have any yellow spiders. Instead, it has lots of diamonds set in platinum bands and a sign saying Free champagne for engaged couples. Make your ring-choosing experience a special one. There’s nothing about replicas or fakes, and I start to feel nervous. What if Sam misunderstood? What if I end up buying a real emerald ring out of embarrassment and have to spend the rest of my life paying it off?

And where is Sam, anyway? He promised to pop along and introduce me to his friend. Apparently he works just round the corner—though he didn’t reveal exactly where. I turn and survey the street. It’s kind of weird that we’ve never met properly, face-to-face.

There’s a man with dark hair walking briskly on the other side of the road, and for a brief moment I think perhaps that’s him, but then a deep voice says, “Poppy?”

I turn—and, of course, that’s him: the guy with the dark rumpled hair striding toward me. He’s taller than I remember from my glimpse of him in the hotel lobby but has the same distinctive thick eyebrows and deep-set eyes. He’s wearing a dark suit and immaculate white shirt and a charcoal tie. He flashes me a brief smile, and I notice that his teeth are very white and even.

Well. They won’t be for much longer if he doesn’t go to the dentist.

“Hi. Poppy.” As he approaches he hesitates, then extends a hand. “Good to meet you properly.”

“Hi.” I smile awkwardly back and we shake hands. He has a nice handshake. Warm and positive.

“So, Vivien’s definitely staying with us.” He tilts his head. “Thanks again for your insight.”

“No problem!” I shrug. “It was nothing.”

“Seriously. I appreciate it.”

This is odd, talking face-to-face. I’m distracted by seeing the contours of his brow and his hair rippling in the breeze. It was easier by text. I wonder if he feels the same way.

“So.” He gestures at the jewelry shop. “Shall we?”

This shop is seriously cool and expensive. I wonder if he and Willow came and chose their ring here. They must have. I’m almost tempted to ask him—but somehow I can’t quite bring myself to mention her. It’s too embarrassing. I know far too much about them.

Most couples, you meet at the pub or at their house. You talk about anodyne stuff—Holidays, hobbies, Jamie Oliver recipes. Only gradually do you venture on to personal stuff. But with these two, I feel as if I’ve been pitched straight into some fly-on-the-wall documentary and they don’t even know it. I found an old email last night from Willow which just said, Do you know how much PAIN you have caused me, Sam? Quite apart from all the fucking BRAZILIANS??

Which is something I really wish I hadn’t read. If I ever meet her, that’s the only thing I’m going to be able to think about. Brazilians.

Sam has pressed the buzzer and is ushering me into the smart, dimly lit shop. At once a girl in a dove-gray suit comes up.

“Hello, may I help?” She has a soft, honeylike voice, which completely suits the muted décor of the shop.

“We’re here to see Mark,” Sam says. “It’s Sam Roxton.”

“That’s right.” Another girl in dove-gray nods. “He’s waiting for you. Take them through, Martha.”

“May I get you a glass of champagne?” says Martha, giving me a knowing smile as we walk along. “Sir? Champagne?”

“No, thanks,” says Sam.

“Me neither,” I chime in.

“Are you sure?” She twinkles at me. “It’s a big moment for the two of you. Just a little glass to take off the nerves?”

Oh my God! She thinks we’re an engaged couple. I glance at Sam for help—but he’s typing something on his phone. And there’s no way I’m launching into the story of losing my priceless heirloom ring in front of a bunch of strangers and hearing all the gasps of horror.

“I’m fine, honestly.” I smile awkwardly. “It’s not—I mean, we’re not—”

“That’s a wonderful watch, sir!” Martha’s attention has been distracted. “Is that vintage Cartier? I haven’t seen one quite like it.”

“Thanks.” Sam nods. “Got it at auction in Paris.”

Now that I notice it, Sam’s watch is quite amazing. It’s got an old leather strap, and the dull gold dial has the patina of another age. And he got it in Paris. That’s pretty cool.

“Goodness.” As we walk, Martha takes my arm and leans in, lowering her voice, girl-to-girl. “He has exquisite taste. Lucky you! You can’t say the same of all the men who come in here. Some of them go for absolute horrors. But a man who buys himself vintage Cartier has got to be on the right track!”

This is painful. What do I say?

“Er … right,” I mumble, staring at the floor.

“Oh, I’m sorry, I don’t mean to embarrass you,” says Martha charmingly. “Please let me know if you change your mind about the champagne. Have a wonderful session with Mark!” She ushers us into a large back room with a concrete floor, lined with metal-fronted cabinets. A guy in jeans and rimless specs gets up from a trestle table and greets Sam warmly.

“Sam! Been too long!”

“Mark! How are you doing?” Sam claps Mark on the back, then steps aside. “This is Poppy.”

“Good to meet you, Poppy.” Mark shakes my hand. “So, I understand you need a replica ring.”

I feel an immediate lurch of paranoia and guilt. Did he have to say it out loud like that, for anyone to hear?

“Very temporarily.” I keep my voice almost to a whisper. “Just while I find the real thing. Which I will, really, really soon.”

“Understood.” He nods. “Useful to have a replica anyway. We do a lot of replacements for travel and so forth. Normally we only make replicas of jewelry we’ve designed ourselves, but we can make the odd exception for friends.” Mark winks at Sam. “Although we do try to be a little discreet about it. Don’t want to undermine our core business.”

“Yes!” I say quickly. “Of course. I want to be discreet too. Very much so.”

“Do you have a picture? A photo?”

“Here.” I haul out a photo which I printed off my computer this morning. It’s of Magnus and me at the restaurant where he proposed. We got the couple at the next table to take a picture of us, and I’m holding up my left hand proudly, with the ring clearly visible. I look absolutely giddy—which, to be fair, is how I was feeling.

Both men stare at it in silence.

“So, that’s the guy you’re marrying,” says Sam at last. “The Scrabble fiend.”

“Yes.”

There’s something in his tone which makes me feel defensive. I have no idea why.

“His name’s Magnus,” I add.

“Isn’t he the academic?” Sam’s frowning at the photo. “Had the TV series?”

“Yes.” I feel a flash of pride. “Exactly.”

“That’s a four-carat emerald, I’d guess?” Mark Spencer looks up from squinting at the photo.

“Maybe,” I say helplessly. “I don’t know.”

“You don’t know how many carats your engagement ring is?”

Both men shoot me an odd look.

“What?” I feel myself flush. “I’m sorry. I didn’t know I’d lose it.”

“That’s very sweet,” says Mark with a wry little smile. “Most girls have it down to the nearest decimal. Then they round up.”

“Oh. Well.” I shrug to cover my embarrassment. “It’s a family ring. We didn’t really talk about it.”

“We have a lot of mounts in stock. Let me look… .” Mark pushes his chair away and starts searching through the metal drawers.

“He still doesn’t know you’ve lost it?” Sam jerks a thumb at the picture of Magnus.

“Not yet.” I bite my lip. “I’m hoping it’ll turn up and … ”

“He’ll never have to know you lost it,” Sam finishes for me. “You’ll keep the secret safe till your deathbed.”

I look away, feeling twingey with guilt. I don’t like this. I don’t like having secrets from Magnus. I don’t like being the kind of person who has assignations behind her fiancé’s back. But there’s no other way.

“So, I’m still getting Violet’s emails on this.” I gesture at him with the phone, to distract myself. “I thought the tech people were sorting it out.”

“So did I.”

“Well, you’ve got some new ones. You’ve been asked about the Fun Run four times now.”

“Hmm.” He barely nods.

“Aren’t you going to answer? And what about your hotel room for this conference in Hampshire? Do you need it for one night or two?”