The assassination of William Lamb began at 6:45 P.M. on a soft June night. Spectators packed the killing ground, a sales room on the second floor of Sotheby’s, in London. The victim wore the raiment of his caste, a crisp tuxedo. A few yards in front of where he sat, blazing in its spotlight on a plinth beside the auctioneer, was a 1,109-carat top-color white diamond called Lesedi La Rona, the vessel of Lamb’s hopes for a bold new way to sell rough diamonds. His wife had bought him new shoes for the occasion, the toe caps spattered with faux gems. He wore socks patterned with jaunty slashes of color.

The Lesedi diamond opened at $50 million and struggled from the start. Fifty-one million dollars, someone offered, and too long after that, $52 million. This was not the scenario that Lamb had imagined in his dreams. In that version, a forest of bidding paddles would have shot up in the room as eager buyers drove the price north of $100 million. Just the month before, Lucara Diamond Corp., the company Lamb runs and the owner of the diamond, had sold an 813-carat stone for $63.1 million—the highest price ever paid for a rough diamond. Now here was this even greater jewel, the second-biggest diamond ever found, and where were the clamoring suitors? Just that morning at breakfast, Lamb’s boss, Lukas Lundin, a Swedish oil and mining tycoon whose family is Lucara’s largest shareholder, had explained to me that the company’s commission arrangement with Sotheby’s meant the stone would have to reach $150 million for the auctioneer to make decent money. “Up to $100 million,” he said, “they make almost nothing.”

“You have a buyer already, don’t you?” I said.

“We think we do,” Lundin replied, slicing into a poached egg. He glanced out the window at the trees of Green Park and at the traffic on Piccadilly flowing by in the rain. “But,” he raised his knife in a cautionary gesture, “you never know.”

Nine hours later he sure found out, sitting in front of Lamb while the auctioneer tried to drag up the price in increments of $500,000. At $61 million, still short of the reserve, the price would not budge. The gavel came down and brought the failed auction to a close.

Ashen-faced, Lamb got to his feet. A pack of diamond dealers closed around him. I thought of Julius Caesar at the Senate on the Ides of March. Those surrounding Lamb represented the old diamond order, whose grip Lamb had just tried to loosen. By selling the great diamond at auction, Lamb had attempted to replace the story some of these men tell the world with another story, and the daggers bristling from his back had been planted there by those who did not like the switch.

A Light Within

With the failure of the Sotheby’s auction, William Lamb released me from the terms of a non-disclosure agreement with a ruinous breach penalty. By signing it, I had gained exclusive access over a period of six months not only to Lesedi La Rona but to the deliberations of the owners—their doubts, their anxieties, their hopes—and to the story of discovery that had set the attempted sale in motion. Within hours of signing the agreement, earlier this year, I was over the ocean and halfway to Botswana to see the diamond for myself. It was, I knew, an apple-size, top-color white, by far the largest in a phenomenal run of super-large diamonds that had lately come on the market: 550 carats, 404 carats, 813 carats, and on and on. This one left the others in the dust: 1,109 carats. How miners now manage to recover such enormous gemstones without smashing them to bits in the mill is itself an astonishing feat of engineering, for which much of the credit belongs to Lamb and his close circle. Yet despite its spectacular success in doing just that, and now possessing a stone that the greatest diamantaires in the world were panting to examine, Lucara had shut the diamond away under tight security. The company would not show it until it had the answer to a question: was there a way to extract more money from this diamond than the usual selling practice would deliver?