“Know how much you can afford, never overstretch yourself, and try to remember that the other side are also hoping to make a profit. And build good contacts because they’ll be your lifeline during bad times, as only one thing is certain in banking—you will experience bad times. And by the way,” he’d added, “never buy retail.”

“Who taught you that?” Seb had asked.

“Jack Benny.”

Armed with sound advice from both Cedric Hardcastle and Jack Benny, Seb went in search of an engagement ring. The contact had been suggested by his old school chum, Victor Kaufman, who now worked on the foreign exchange desk at his father’s bank, just a few blocks away from Farthings. He’d advised Seb to visit a Mr. Alan Gard in Hatton Garden.

“He’ll supply you with a larger stone, at half the price of any jeweller on the high street.”

Seb was eating on the move and taking a taxi because he knew he had to be back at his desk within the hour if he didn’t want to fall foul of Adrian Sloane yet again. It pulled up outside a green door that Seb would have passed without noticing if the number 47 hadn’t been painted neatly on it. There was nothing to hint of the treasures that lay within. Seb realized that he must be dealing with a private and cautious man.

He pressed the bell, and a moment later a Dickensian figure wearing a skull cap and with long black ringlets greeted him. When Seb said he was a friend of Victor Kaufman, he was quickly ushered through to Mr. Gard’s inner sanctum.

A wiry man, no taller than five feet, and dressed casually in an open-necked shirt and well-worn jeans, rose from behind his desk and gave his potential customer a warm smile. When he heard the name Kaufman, the smile broadened and he rubbed his hands together as if he was about to roll some dice.

“If you’re a friend of Saul Kaufman, you’re probably expecting to get the Koh-I-Noor for five pounds.”

“Four,” said Seb.

“And you’re not even Jewish.”

“No,” said Seb, “but I was trained by a Yorkshireman.”

“That explains everything. So how can I help you, young man?”

“I’m looking for an engagement ring.”

“And who’s the lucky girl?”

“An American, called Sam.”

“Then we’ll have to find Sam something special, won’t we?” Mr. Gard opened his desk drawer, took out a vast key ring, and selected a single key from the bunch. He walked across to a large safe embedded in the wall, unlocked the heavy door, and opened it to reveal a dozen neatly stacked trays. After hesitating for a moment, he selected the third tray from the bottom, pulled it out, and placed the contents on his desk.

Several small diamonds winked up at Seb. He studied them for a few moments before shaking his head gravely. The gemologist made no comment. He returned the tray to the safe and extracted the one above.