The young prince promptly launched a devastating and costly war against Iran’s proxy in neighboring Yemen and imposed a blockade on upstart Qatar that plunged the Gulf region into crisis. Mainly, he plotted and schemed inside the royal court to weaken his rivals, all with the blessing of his father, the king. Aged and ill with diabetes, the king knew his reign would not be long. It was customary in the House of Saud that brother succeed brother. But the king upended that tradition by designating his son the crown prince and thus next in line to the throne. At just thirty-three, he became the de facto ruler of Saudi Arabia and leader of a family whose net worth was in excess of $1 trillion.

But the future king knew that his country’s wealth was largely a mirage; that his family had squandered a mountain of money on palaces and trinkets; that in twenty years, when the transformation from fossil fuels to renewable sources of energy was complete, the oil beneath Saudi Arabia would be as worthless as the sand that covered it. Left to its own devices, the Kingdom would return to what it once was, an arid land of warring desert nomads.

To spare his country this calamitous future, he resolved to drag it out of the seventh century and into the twenty-first. With the help of an American consulting firm, he produced an economic blueprint he grandly called The Way Forward. It envisioned a modern Saudi economy powered by innovation, foreign investment, and entrepreneurship. No longer would its pampered citizenry be able to count on government jobs and cradle-to-grave benefits. Instead, they would actually have to work for their living and study something other than the Koran.

The crown prince understood that the workforce of this new Saudi Arabia could not be comprised of men alone. Women would be required, too, which meant the religious shackles that kept them in a state of near slavery would have to be loosened. He granted them the right to drive, long forbidden, and allowed them to attend sporting events where men were present.

But he was not content with small religious reforms. He wanted to reform the religion itself. He pledged to shut down the pipeline of money that fueled the global spread of Wahhabism, Saudi Arabia’s puritanical version of Sunni Islam, and crack down on private Saudi support for jihadi terrorist groups such as al-Qaeda and ISIS. When an important columnist from the New York Times wrote a flattering portrait of the young prince and his ambitions, the Saudi clerical establishment, the ulema, seethed with a sacred rage.

The crown prince jailed a few of the religious hotheads and, unwisely, a few of the moderates, too. He also jailed supporters of democracy and women’s rights and anyone foolish enough to criticize him. He even rounded up more than a hundred members of the royal family and Saudi Arabia’s business elite and locked them away in the Ritz-Carlton Hotel. There, in rooms without doors, they were subjected to harsh interrogations, sometimes at the hands of the crown prince himself. All were eventually freed, but only after surrendering more than $100 billion. The future king claimed the money had been acquired through bribery and kickback schemes. The old way of doing business in the Kingdom, he declared, was over.

Except, of course, for the future king himself. He accumulated personal wealth at a dizzying pace and spent it lavishly. He bought whatever he wanted, and what he couldn’t buy he simply took. Those who refused to bend to his will received an envelope containing a single .45-caliber round.

Which prompted, mainly in the West, a great reassessment. Was KBM truly a reformer, wondered the policy makers and the Middle East experts, or was he just another power-mad desert sheikh who was locking away his opponents and enriching himself at the expense of his people? Did he really intend to remake the Saudi economy? End the Kingdom’s support for Islamic zealotry and terrorism? Or was he merely trying to impress the smart set in Georgetown and Aspen?

For reasons Sarah could not explain to friends and colleagues in the art world, she initially counted herself among the skeptics. And so she was understandably reticent when Khalid, during a visit to New York, asked to see her. Sarah eventually agreed, but only after first clearing it with the security division at Langley, which was watching over her from afar.

They met in a suite at the Four Seasons Hotel, with no bodyguards or aides present. Sarah had read the many laudatory pieces about KBM in the Times and had seen photographs of him wearing a traditional Saudi robe and headdress. In his tailored English suit, however, he was a far more impressive figure—eloquent, cultured, sophisticated, dripping with confidence and power. And money, of course. An unimaginable amount of money. He intended to use a small portion of it, he explained, to acquire a world-class collection of paintings. And he wanted Sarah to serve as his adviser.

“What do you intend to do with these paintings?”

“Hang them in a museum I’m going to build in Riyadh. It will be,” he said grandly, “the Louvre of the Middle East.”

“And who will visit this Louvre of yours?”

“The same people who visit the Louvre in Paris.”

“Tourists?”

“Yes, of course.”

“In Saudi Arabia?”

“Why not?”

“Because the only tourists you allow are the Muslim pilgrims who visit Mecca and Medina.”

“For now,” he said pointedly.

“Why me?”

“Are you not the curator of the Nadia al-Bakari Collection?”

“Nadia was a reformer.”

“So am I.”

“Sorry,” she said. “Not interested.”

A man like Khalid bin Mohammed was not used to rejection. He pursued Sarah ruthlessly—with phone calls, flowers, and lavish gifts, none of which she accepted. When she finally relented, she insisted her work would be pro bono. Though she was intrigued by the man known as KBM, her past would not allow her to accept a single riyal from the House of Saud. Furthermore, for his sake and hers, their relationship would be strictly confidential.

“What shall I call you?” she asked.

“Your Royal Highness will be fine.”

“Try again.”

“How about Khalid?”

“Much better.”

They acquired swiftly and aggressively, at auction and through private sales—Postwar, the Impressionists, Old Masters. They did little negotiating. Sarah would name her price, and one of Khalid’s courtiers would handle the payment and see to the shipping arrangements. They conducted their shopping spree as quietly as possible and with the subterfuge of spies. Still, it didn’t take long for the art world to realize there was a major new player in their midst, especially after Khalid plunked down a cool half billion for Leonardo’s Salvator Mundi. Sarah had advised against the purchase. No painting, she argued, save for perhaps the Mona Lisa, was worth that kind of money.

While building the collection, she spent many hours alone in Khalid’s company. He spoke to her of his plans for Saudi Arabia, at times using Sarah as a sounding board. Gradually, her skepticism faded. Khalid, she thought, was an imperfect vessel. But if he were able to bring real and lasting change to Saudi Arabia, the Middle East and the broader Islamic world would never be the same.

All that changed after Omar Nawwaf.

Nawwaf was a prominent Saudi journalist and dissident who had taken refuge in Berlin. A critic of the House of Saud, he held Khalid in particularly low esteem, regarding him as a charlatan who whispered sweet nothings into the ears of gullible Westerners while enriching himself and jailing his critics. Two months earlier, Nawwaf had been brutally murdered inside the Saudi consulate in Istanbul, and his body dismembered for disposal.