I’m not sure that’s made things any clearer.

The interpreter murmurs furiously in Mr. Yamasaki’s ear and after a moment looks at me.

“You may present.”

Mr. Yamasaki turns and all his colleagues follow suit, folding their arms expectantly and lining up in a row. Around the lobby I can see a few interested glances from other groups of businesspeople.

“Where are you?” I murmur desperately into the phone.

“Third floor,” comes the man’s voice after a moment. “Half a minute. Don’t lose him.”

“Begin,” the man in steel spectacles says pointedly.

Some people nearby have turned to watch. Oh God. How did I get myself into this? Number one, I can’t sing. Number two, what do I sing to a Japanese businessman I’ve never met before? Number three, why did I say singing telegram?

But if I don’t do something soon, twenty people might lose their jobs.

I make a deep bow, to spin out some more time, and all the Japanese bow back.

“Begin,” repeats the man in steel spectacles, his eyes glinting ominously.

I take a deep breath. Come on. It doesn’t matter what I do. I only have to last half a minute. Then I can run away and they’ll never see me again.

“Mr. Yamasaki … ” I begin cautiously, to the tune of “Single Ladies.” “Mr. Yamasaki. Mr. Yamasaki, Mr. Yamasaki.” I shimmy my hips and shoulders at him, just like Beyoncé.

“Mr. Yamasaki, Mr. Yamasaki.”

Actually, this is quite easy. I don’t need any lyrics—I can keep singing “Mr. Yamasaki” over and over. After a few moments, some of the Japanese even start singing along and clapping Mr. Yamasaki on the back.

“Mr. Yamasaki, Mr. Yamasaki. Mr. Yamasaki, Mr. Yamasaki.” I lift my finger and waggle it at him with a wink. “Ooh-ooh-ooh … ooh-ooh-ooh … ”

This song is ridiculously catchy. All the Japanese are singing now, apart from Mr. Yamasaki, who’s standing there, looking delighted. Some nearby delegates have joined in with the singing, and I can hear one of them saying, “Is this a flash mob thing?”

“Mr. Yamasaki, Mr. Yamasaki, Mr. Yamasaki … Where are you?” I mutter into the phone, still beaming brightly.

“Watching.”

“What?” My head jerks up and I sweep the lobby.

Suddenly my gaze fixes on a man standing alone, about thirty yards away. He’s wearing a dark suit and has thick black rumpled hair and is holding a phone to his ear. Even from this distance I can see that he’s laughing.

“How long have you been there?” I demand furiously.

“Just arrived. Didn’t want to interrupt. Great job, by the way,” he adds. “I think you won Yamasaki round to the cause, right there.”

“Thanks,” I say sarcastically. “Glad I could help. He’s all yours.” I bow to Mr. Yamasaki with a flourish, then turn on my heel and head swiftly toward the exit, ignoring the disappointed cries of the Japanese. I’ve got more important stuff to worry about than arrogant strangers and their stupid business deals.

“Wait!” The man’s voice follows me through the receiver. “That phone. It’s my PA’s.”

“Well, she shouldn’t have thrown it away, then,” I retort, pushing the glass doors open. “Finders keepers.”

There are twelve tube stops from Knightsbridge to Magnus’s parents’ house in North London, and as soon as I resurface from the underground I check the phone. It’s flashing with new messages—about ten texts and twenty emails—but there are only five texts for me and none with news about the ring. One’s from the police, and my heart leaps with hope—but it’s only to confirm that I’ve filed a report and asking if I want a visit from a victim support officer.

The rest are all text messages and emails for Violet. As I scroll down them, I notice that Sam features in the subject heading of quite a few of the emails. Feeling like Poirot again, I check back on the numbers called function and, sure enough, the last number that called this phone was Sam Mobile. So that’s him. Violet’s boss. Dark-rumpled-hair guy. And to prove it, her email address is [email protected].

Just out of the mildest curiosity, I click on one of the emails. It’s from [email protected], and the subject is Re: Dinner?

Thanks, Violet. I’d appreciate you not mentioning any of this to Sam. I feel a little embarrassed now!

Ooh. What’s she embarrassed about? Before I can stop myself, I’ve scrolled down to read the previous email, which was sent yesterday.