Gabriel and Sarah joined Mikhail on the foredeck. The two guards scrutinized them, Sarah especially, but made no offer to escort them to Khalid’s quarters. Unchaperoned, they wandered Tranquillity at their leisure, through the piano lounge and the discotheque, the conference room and the movie cinema, the billiards room, the steam room, the snow room, the ballroom, the fitness center, the archery center, the rock-climbing room, the children’s playroom, and the undersea observation center, where the many species of Red Sea aquatic life darted and frolicked for their private amusement on the other side of the thick glass.

They found Khalid on Deck 4, on the terrace outside the owner’s suite. He was wearing a zippered North Face fleece, faded jeans, and a pair of elegant Italian suede moccasins. The wind was making waves on the surface of a small swimming pool and fanning the flames of the inferno that crackled and spat in the outdoor fireplace. It was the last of his wood, he explained. Otherwise, he was well provisioned with food, fuel, and fresh water. “I can remain at sea for a year or more if necessary.” He rubbed his hands vigorously together. “It’s cold tonight. Perhaps we should go inside.”

He led them into the suite. It was larger than Gabriel’s apartment in Jerusalem. “It must be nice,” he said as he surveyed his opulent surroundings. “I don’t know how I ever managed without a private discotheque or a snow room.”

“They mean nothing to me.”

“That’s because you’re the son of a king.” Gabriel displayed the file Yossi had given him at Ben Gurion. “But you might feel differently if you were merely the king’s half brother.”

“I take it you reviewed the documents I gave you in Jerusalem.”

“We used them only as a starting point.”

“And where did they lead you?”

“Here,” said Gabriel. “To Tranquillity.”

The primary system by which the Kingdom of Saudi Arabia funnels the country’s immense oil wealth to members of the royal family is the official monthly stipend. Not all Saudi royals, however, are created equal. A lowly member of the House of Saud might collect a cash payment of a few thousand dollars, but those with direct blood ties to Ibn Saud receive far more. A grandchild of the Founder typically receives about $27,000 a month; a great-grandchild, about $8,000. Additional payments are available for the construction of a palace, for a marriage, or for the birth of a child. In Saudi Arabia, at least for members of the royal family, there is a financial incentive to procreate.

The largest stipends are reserved for those privileged few at the top of the food chain—the sons of the Founder. He had forty-five in all, including Abdullah bin Abdulaziz. Before his elevation to crown prince, he received a monthly payment of $250,000, or $3 million per year. It was more than enough money to live comfortably, but not lavishly, especially in the Al Saud playgrounds of London and the Côte d’Azur. To supplement his wages, Abdullah siphoned money directly from the state budget or received bribes and kickbacks from Western companies wishing to do business in the Kingdom. A British aerospace firm paid him $20 million in “consulting fees.” He used a portion of the money, explained Gabriel, to purchase a grand house at 71 Eaton Square in Belgravia.

“I believe you dined there recently, did you not?”

Receiving no reply, Gabriel continued with his briefing. Abdullah, he said, was quite good at the other family business—the business of graft and theft—but in 2016 he got himself into serious financial trouble with a string of bad investments and questionable expenditures. He begged His Majesty King Mohammed for a few extra riyals to cover his living expenses. And when His Majesty refused to bail him out, he prevailed upon his next-door neighbor, the owner of 70 Eaton Square, for a loan. The man’s name was Konstantin Dragunov, better known as Konnie Drag to his friends.

“You remember Konstantin, don’t you, Khalid? Konstantin is the Russian billionaire who sold you this ridiculous boat.” Gabriel made a show of thought. “Remind me how much you paid for it.”

“Five hundred million euros.”

“In cash, right? Konstantin insisted the money be wired into one of his accounts at Gazprombank in Moscow before he would agree to leave the boat. A few days later he lent your uncle a hundred million pounds.” Gabriel paused. “I suppose that’s what it means to recirculate petrodollars.”

Khalid was silent.

“He’s an interesting fellow, our Konstantin. He’s a second-generation oligarch, not one of the original robber barons who looted the assets of the old Soviet Union after the fall. Unlike many of the oligarchs, Konstantin is diversified. He’s also quite close to the Kremlin. In Russian business circles it is assumed that most of Konstantin’s money actually belongs to the Tsar.”

“That’s the way it works for people like us.”

“Us?”

“The Tsar and me. We operate through cutouts and fronts. I’m not the nominal owner of this boat, as you call it, and I don’t own the château in France, either.” He glanced at Sarah. “Or the Leonardo.”

“And when people like you are no longer in power?”

“The money and the toys have a way of disappearing. Abdullah has already taken billions from me. And the Leonardo,” he added.

“Somehow you’ll survive.” Gabriel admired Khalid’s view of the Egyptian coast. “But back to your uncle. Needless to say, Abdullah never repaid the hundred million pounds Konstantin Dragunov lent him. That’s because it wasn’t a loan. And it was only the beginning. While you were engaging in court intrigue in Riyadh, Abdullah was doing lucrative business deals in Moscow. He earned more than three billion dollars in the last two years, all through his association with Konstantin Dragunov, which is another way of saying the president of Russia.”

“Why was he so interested in Abdullah?”

“I suppose he wanted an ally inside the House of Saud. Someone who was respected for his political acumen. Someone who hated the Americans as much as he did. Someone who could serve as a trusted adviser to a young and untested future king. Someone who might be able to convince the future king to tilt Moscow’s way and thus expand the Kremlin’s regional influence.” Gabriel turned and looked at Khalid. “Someone who might offer to rid the future king of a meddlesome priest. Or a dissident journalist who was trying to warn the future king about a plot to force him to abdicate.”

“Are you saying Abdullah conspired with the Russians to seize the throne of Saudi Arabia?”

“I’m not saying it, Omar Nawwaf is.” Gabriel drew Hanifa Khoury’s flash drive from his pocket. “I don’t suppose there’s a computer on this boat, is there?”

“Yacht,” said Khalid. “Come with me.”

There was an iMac in the suite’s private study, but Khalid had the good sense not to allow the chief of the Office to impale it with a flash drive. Instead, he led Gabriel down to Tranquillity’s hotel-style business center. It contained a half dozen workstations with Internet-connected computers, printers, and multiline phones tied into the ship’s satellite communications system.

Khalid sat down at one of the terminals and inserted the flash drive. A dialogue box queried him for a user name.