Katya Slatsky was ecstatic.

The moment she hung up her phone and stashed it in her new Prada purse, another lavish gift from him, she excused herself from the party as quickly and discreetly as she could. Then she dashed out the door of the flat, burst into the stairwell, and ran down four flights, too impatient to wait for the elevator, as her thirtysomething friends giggled in her wake, exchanging knowing glances and catty grins over her “urgent business” that had “just come up.”

They all knew whom she was seeing. Thus they all knew where she was going. From the beginning of the affair, Katya had sworn them to secrecy. None of them had been able to keep the secret, of course, and rumors had spread. At first Katya had been terrified, fearing the gossip would get back to Luganov and lead to a sudden end to the fling. But then the president had separated from his wife, Yulia, banishing her from Moscow to some dacha near St. Petersburg. Ever since, Katya had dreamt of the day her paramour would invite her to move in or, better yet, propose.

In her excitement, Katya raced out to the street and fumbled with her keys for a moment before finally finding the right one. She clicked open the driver’s-side door to her brand-new silver BMW, another of his many gifts, buckled up, and roared off to Novo-Ogaryovo, her music blasting and her heart racing. She hadn’t seen him in nearly a week —he was so consumed with his work —and she craved time alone with him.

Twenty minutes later she arrived at the first checkpoint on the outer perimeter of the presidential palace. She pulled to a stop and lowered her window. All the guards recognized her, of course, and she was on the list of expected and approved visitors. But she’d done this enough times to know the strict procedures that had to be followed. One guard asked her to look into a portable retinal scanning device. Another worked his way around the BMW with a mirror attached to a long pole, examining the underside of the chassis for possible explosive devices. Still several more agents carefully checked through the contents of her trunk and glove compartment and beneath the hood of her car, while the K-9 unit checked the sedan inside and out for any whiff of explosives.

Finally cleared with a smile and wave from all of the guards, who were completely dazzled by her stunning good looks, Katya winked back and drove on to her assigned parking spot even as she heard the roar of the presidential helicopter arriving at the landing pad on the north lawn. Now her heart was racing even faster. She was greeted and helped with her overnight bag by the chief steward, who led her to the next checkpoint. There she chatted up the security men, each of whom she knew by name, as she put her things through the X-ray machine and walked through the metal detector. Even after that, she was wanded down for good measure by a female uniformed guard. Katya knew family members weren’t subjected to any of this. Yet she also knew all too well that she was not family. Not yet, anyway. So she didn’t resent any of these measures. The agents were just doing their jobs. They were keeping her lover safe in unsafe times. Still, she looked forward to the day when she finally wore a diamond on her left hand and could come and go as she pleased without any of this hassle.

Not five minutes later, Katya was alone in the enormous bathroom off the master bedroom, changing into a new negligee and dabbing French perfume behind her ears and on her neck. Would tonight be the night? Would he propose to her and sweep her off her feet?

She was trembling with anticipation as she turned off the bathroom lights and slid beneath the silk sheets. Tonight, she felt sure, was going to be a night to remember.

It was well past 11 p.m. when Oleg was at last ready to leave the office.

He had made every call the president had demanded. He’d spun the man’s lies to world leaders and their deputies. He’d conferred with the number-two man in the Russian defense ministry and made sure he knew he had the “president’s deepest appreciation for his steadfast loyalty and dedication to excellence.” He’d dutifully typed up the minutes of the morning meeting with the war cabinet and transmitted them to the classified distribution list, and he had been in and out of Luganov’s office at least a dozen times in between, getting new call lists and assignments and providing the president hourly updates as the man relentlessly drove his government toward a war set to begin in scarcely more than forty-eight hours.

Now, with everything else on his list crossed off, he turned to a task he’d never written down. He plugged a thumb drive into his office computer, copied the hard drive’s contents, and then shut the computer down for the night. Next he put all the classified documents spread out on his desk into his wall safe and locked them up. Then he donned his raincoat and cashmere flat cap, put the thumb drive in his briefcase, and locked the door to his office behind him.

Hardly anyone had gone home. The floor was still humming with activity, and Oleg had no doubt it would continue like that all night. But Luganov had just choppered back to his palace in Novo-Ogaryovo. That meant Oleg was free to go, and he had other work to attend to that most certainly could not be done from inside the Kremlin’s walls.

After his security detail drove him back to his empty house, he excused himself and said he was retiring for the night. Once inside his master bedroom, he locked the door behind him, lit a cigarette, and grabbed the satellite phone from the safe. When it was powered up, he walked over to the windows and pulled the drapes. At some point during the day the rain had turned to flurries, but none of the snow had stuck, and the precipitation had ended for the night. As he dialed the phone, though, he realized how much his hands were trembling, and it was not because of the cold or the wind. He turned and walked into the bathroom and locked the door.

After the fifth ring, someone picked up but said nothing.

“‘A great disaster has befallen Russia,’” Oleg said, citing Solzhenitsyn.

“‘Men have forgotten God,’” the voice at the other end replied. “‘That’s why all this has happened.’”

Then, per their predetermined verification plan, Oleg now cited Dostoyevsky from The Brothers Karamazov. “‘Above all, don’t lie to yourself.’”

“‘The man who lies to himself and listens to his own lie comes to a point that he cannot distinguish the truth within him, or around him,’” the voice replied.

“‘And he loses all respect for himself and for others —and having no respect he ceases to love,’” Oleg added with a sigh.

“It’s good to hear your voice,” Marcus said at last.

“It’s good to hear yours,” Oleg said. “We can speak freely? You’re certain this is secure?”

“Absolutely.”

“Where are you right now?”

“Closer than you might imagine.”

“What does that mean?”

“I’m in Moscow.”

“You’re here? How? I thought —”

“I know. I did, but I came back. Don’t ask me how. Suffice it to say your security services don’t know I’m here, and for now I’d like to keep it that way.”

“Of course. Do you have access to a car?”

“I do.”

“Good —that’s very good.” Oleg quickly recalculated his options. “Listen carefully. I’ve got a gift for you.”

“A gift?”

“Files.”

“What kind of files?”

“Everything off my office hard drive.”

“Everything?”

“War plans. Strategic memos. Transcripts of every conversation the . . .”

Oleg hesitated. He didn’t want to use Luganov’s name or title even though Marcus had assured him nothing they said could be intercepted. But he realized there was no reason to hold back now. If the FSB were on to him, if they could hear what he was saying, he was a dead man. Omitting a few key words here or there wasn’t going to make any difference at all.

“. . . the president has had with other world leaders and members of his cabinet,” he continued. “Emails, voice messages, my private notes. I’m ready to give it all to you. I was calling to ask you how to do that, but maybe we can just meet.”

Now it was Marcus who hesitated. Finally he said, “Of course, but I . . . I don’t know what to say, except thank you.”

“Don’t thank me too soon,” Oleg countered. “It’s not going to be enough.”

“What do you mean?”

“I’m giving you the mother lode, and it will give your people tremendous insights into everything Luganov is doing, thinking, ordering,” Oleg said. “But it won’t stop this thing. It can’t. Events are unfolding too fast. He’s going to war even faster than I’d thought, faster than he said.” Oleg briefed Marcus on how accelerated the timetable had become.

“You’re telling me the invasion is now set to begin in just forty-eight hours?” Marcus asked.

“Correct.”

“Then we need to get you out now, before it’s too late,” Marcus said.

“No, that won’t solve anything,” Oleg replied.

“It’s okay,” Marcus responded. “I have a plan. We can get you out of the country and someplace safe, somewhere they’ll never find you.”

“No, please, that’s not what I want,” Oleg protested. “You don’t understand. There’s only one way to stop this war from happening, and it’s not by me running.”

“Then what?” Marcus asked.

Oleg paused, took a deep breath, and then said, “I need to kill the president.”