The flight through the Highlands was beyond picturesque, but Mars wasn’t looking out the window. He was looking at Janice Won.

She was dividing her attention between the terrain, the movement of the clouds in the sky, and a laptop in front of her with current weather conditions and the forecast and a map of the area.

Mars smiled, telling himself that he had chosen his weapon well.

He’d made Won believe that by going rogue, defying her orders from North Korea, she could deal a crushing blow to her nation’s enemies, a feat that would certainly be rewarded upon her triumphant return. He convinced her there would be no comebacks on her nation, and he knew she would be thinking that it would be Russia and some strange Englishman who would be seen as the actual perpetrators.

But that was not, in fact, Mars’s plan. No, he intended for North Korea to take the fall for this completely, and in so doing protect Russia from any blame.

Janice Won wasn’t just his weapon; she was also his decoy, his nation’s “get out of jail free” card.

Won looked up at him and spoke into her headset. “How far to the castle?”

Mars pointed in the direction they were flying. “Castle Enrick is on the banks of Loch Ness. Not far.”

Won adjusted her microphone and then moved over to sit next to David Mars. She brought her laptop with her and turned it to him.

“I’ve been running numbers on the potential effects of the attack as we’ve planned it so far.”

“Prognosticating the damage? What have you determined?”

“While working in Sweden I learned that in the West there exists no environmental warning system to alert a population that it’s under attack with a plague weapon, and no widely available and rapid tests. If the delivery of the aerosol is covert, a population would only know it had been subjected to a biological attack with plague when patients began flooding into hospitals and clinics, by which time it would be too late for many of them.”

Mars knew this from Won already. Impatiently, he said, “Numbers of casualties?”

“As you know, with primary infection, the patient’s course becomes irreversible approximately eight hours after infection if not given a large dose of antibiotics, which then must be administered daily for ten days or so. Secondary pneumonic plague results from metastatic spreading by the primary population. It is not quite as deadly, but if we successfully mask our attack so that the primaries remain unaware they’ve been exposed to the bacteria, allowing them to return to their offices and embassies, it will delay treatment for those who pick it up secondarily. If we manage this, we can expect roughly forty to sixty percent mortality in the secondary population.”

Mars was satisfied with this, but said, “Tertiary plague? What’s the mortality?”

Won shook her head. “The West will know what has happened by day ten or so when all four hundred attendees of the conference suddenly die. By the time the secondaries infect the tertiaries, most everyone will be given massive quantities of antibiotics, and the majority of the tertiaries should survive except for the very old, the very young, or the very infirm. Say five percent mortality, no more. But this is an exponential formula, meaning each population, primary, secondary, and tertiary, will be successively larger, so five percent mortality of the tertiary population will still be orders of magnitude larger than the total mortality of the primary field.”

Won straightened her back with pride. “This weapon of ours will cut a swath of destruction deep in the intelligence community of the West, but the destruction will be carried out in the first ten days. After the second week, many more will die, but there will be few new victims.”

“Total estimation of losses to the Five Eyes?”

“I’ve looked at the known staffing at embassies, intelligence agencies, and military and law enforcement facilities where the conference attendees work. My rough calculation is that in addition to virtually all of the first four hundred infected, another four to five thousand secondaries will die.”

He was astonished, even though the plan had been his. He did not have Won’s resources to determine the outcome, and was just assuming the number would have been closer to one thousand.

In his excitement he reached out and squeezed Won on the forearm. She looked down at his grasp as if he had placed a tarantula on her skin.

Mars slipped his hand off quickly.

“Five thousand,” Mars said.

Won relaxed a little but kept looking at her arm. “Four to five thousand, to be precise. Plus the original four hundred. Devastating to Western intelligence,” she added.

“Quite,” said Mars. “It will take generations for them to recover.”

Won closed her laptop, then turned to Mars. “My disease will work. If your plan works, together we will take out a sizable portion of the world intelligence community arrayed against my nation. Arrayed against Russia.”

“Yes,” Mars said.

Now Won’s eyes narrowed and she looked at the bearded older man seated next to her. “But not arrayed against you.”

The sixty-two-year-old cocked his head. “What do you mean by that?”

“Mr. Mars, I still find it difficult to trust you, because I do not understand your motivations. I must know why you are doing this.”

She was pressing him and, as much as it annoyed him, again he did have to concede that her demands were reasonable. He said, “Because I want to literally destroy the U.S. and UK intelligence services.”

“I will ask you one more time . . . Why?”

Mars heaved his chest and exhaled slowly. “I want to destroy these organizations, because, Ms. Won, my wife, my son, and my daughter were all killed by the Five Eyes.”

Janice Won put a hand to her mouth and held it there for some time.

Mars added, “Clear now, isn’t it?”

She nodded slowly, and when she removed her hand she took a moment, seemingly to clear her thoughts of all but the science of the operation.

“Tell me about the crop duster we will use.”

Mars was glad that matter was dealt with. He himself went back to the operational issues at hand. “It will take off from a makeshift airfield, twenty-two miles west of the castle. I’ve looked at previous Five Eyes conferences, and the security preparations don’t include no-fly zones. There will be security in helicopters that might run our aircraft out of the area, but we should be able to get one good pass over the castle before that happens.”

Won said, “We will only need one pass. There will be four canisters to the weapon; with the nozzles completely open, the bacteria will fire from each canister in twelve seconds. It will release more than enough spores to do maximum damage.” She turned to Mars now. “Of course, your pilot will have to be very good.”