Shit .

Diamanté is in a black, open-top Porsche, heading down the gravel at speed toward the front gates, which are hastily being opened by the security guard.

“Noooo!” I wail before I can stop myself.

As Diamanté pauses to exit, she flicks a V-sign back at the house and the next minute is out on the street. In her other hand I can just see Sadie’s necklace, wrapped around her fingers, glinting in the sunshine.

THIRTEEN

There’s only one possibility: They’re not rhinestones, they’re diamonds. The necklace is studded with rare antique diamonds and worth millions of pounds. It’s got to be that. There’s no other reason I can think of that Uncle Bill would be so interested in it.

I’ve Googled all sorts of websites on diamonds and jewelry, and it’s amazing what people will pay for a 10.5-carat D-color diamond mined in 1920.

“How big was the biggest stone in the necklace?” I say yet again to Sadie. “About.”

Sadie sighs noisily. “Half an inch or so?”

“Was it very sparkly? Did it look flawless at all? That could affect its value.”

“You’re terribly interested in the value of my necklace all of a sudden.” Sadie gives me a resentful look. “I didn’t think you were so mercenary.”

“I’m not mercenary!” I say indignantly. “I’m just trying to work out why Uncle Bill was after it! He wouldn’t waste his time unless it was valuable.”

“What difference does it make if we can’t lay our hands on it?”

“We will lay our hands on it.”

I have a plan, and it’s a pretty good one. I’ve been using all my detective skills in the few days since we got back from Uncle Bill’s house. First of all, I found out about Diamanté’s next Tutus and Pearls catwalk show. It’s this Thursday at the Sanderstead Hotel, 6:30 p.m., private guest list. The only trouble was, I couldn’t see Diamanté putting me on the private guest list in a million years, bearing in mind I’m not a photographer from Hello! or one of her celebrity chums or have four hundred quid to spend on a dress. So then came my master stroke. I emailed Sarah in a friendly way and said I’d really like to support Diamanté in her fashion venture and could I come and talk to Uncle Bill about it? Maybe I would just drop over to the house on spec, I suggested. Maybe tomorrow!!! And I added a few smiley faces for good measure.

Sarah immediately emailed back that Bill was a little busy right now and I shouldn’t come tomorrow, but she could talk to Diamanté’s personal assistant. And the next thing I knew, two tickets were biked to my door. Honestly, it’s so easy to get what you want from people if they think you’re a psycho.

The only downer is that the second and crucial part of my plan-talk to Diamanté and persuade her to give me the necklace straight after the show-has failed so far. Her assistant won’t tell me where she is or give me her mobile phone number. She did allegedly pass on a message, but obviously I haven’t heard anything. I mean, why would Diamanté bother to call her nonentity of a nonmillionaire cousin?

Sadie’s tried going to Diamanté’s office in Soho, to see if she can catch her and the necklace-but apparently Diamanté never sets foot there. It’s staffed by assistants, and all the clothes are made by some company in Shoreditch. So that’s no good.

There’s only one thing for it. I’m going to have to go along to the show, wait until it’s over, then grab Diamanté and somehow talk her there and then into giving the necklace to me.

Or, you know. Pinch it.

With a sigh, I close down the jewelry website and swivel around to survey Sadie. Today she’s wearing a silver dress which apparently she desperately wanted when she was twenty-one, but her mother wouldn’t buy it for her. She’s sitting on the sill of the open window, her feet dangling above the street below. The dress is backless except for two thin silver straps over her slender shoulders, and there’s a rosette at the small of her back. Of all the ghost dresses she’s worn, this is my favorite.

“The necklace would look amazing with that dress,” I say impulsively.

Sadie nods but doesn’t say anything. There’s a low-slung, dispirited cast to her shoulders, which isn’t exactly surprising. We were so near to it. We saw it. And then we lost it.

I watch her anxiously for a moment. I know Sadie hates “droning on about things.” But maybe she’d feel better if she talked. Just a little bit.

“Tell me again -why is the necklace so special to you?”

For a while Sadie says nothing, and I wonder if she even heard the question.