The fights were brutish and short. He was a canny fighter, quick to pick up on an opponent’s weaknesses. He would circle for a minute or two, avoiding the sweaty clenches and ungainly wrestling that were the hallmarks of amateur brawls. Then he would move in. A jab to the jaw, a punch to the gut, and a roundhouse to the side of the head. It rarely lasted longer than that. He prided himself on his economy.

He knew that the trait was dangerous and, worse, self-destructive. He also knew that it involved his addiction to risk. He found himself challenging bigger men, venturing into openly dangerous establishments. He began to lose, but even then he was unable to cure himself of this flaw. During his climbs, he sought out uncharted routes. He hungered for the impossible face. He yearned to go higher, farther, and faster.

Then one day, it went away. The fighting. The desire to master a stretch of vertical granite. The need to endanger his life to feel alive. Gone like that. He hung up his gear and decided that that part of his life was finished.

People whispered that it was because of the avalanche. They said he’d lost his nerve. They were wrong. He hadn’t quit. He’d just found a bigger rush. And it was on a concrete highway, not on a vertical face.

He was twenty-one. It was a Sunday night and he was coming back to Aspen after a weekend doing free ascents up Angels Landing, a two-thousand-foot slab of red rock in Zion National Park. As usual, the traffic through the mountains was a nightmare. A Ford Bronco in front of him tried to pass the eighteen-wheeler a few vehicles up. The Bronco was old and consumptive, hopelessly slow, and it collided with an even bigger juggernaut coming the other way. The driver died instantly. The passenger was alive when Jonathan reached her. She was a girl, fourteen at most. Jonathan got her out of the car and laid her on the ground. The gearshift had pierced her chest and blood was spurting from the wound like a ruptured hydrant. With only his patrolman’s training to rely on-knowing only vaguely what to do-he’d rammed his fist into the perforation, keeping pressure on the ruptured artery and arresting the loss of blood. The girl was conscious the entire time. She never said a word. She just stared up at him with his hand buried inside her ribs until the ambulance arrived.

All that time, he could feel her heart beating…actually feel the organ itself, pumping against his hand.

The ultimate rush.

He quit his job the next week and enrolled in college to study medicine.

Jonathan’s thoughts came back to the here and now. Turning away from the window, his eyes fell on Emma’s night table. It stood as she’d left it. An open bottle of mineral water. Reading glasses balanced on a stack of romance novels. “You don’t understand,” she’d said once, trying to explain why she was so slavishly devoted to stories about strapping Scotsmen and time-traveling buccaneers who rescued damsels in distress and lived in castles on the Firth of Forever. She liked them because they were predictable. Happy ending guaranteed. It was an antidote to her job where hardly anything ended happily, or, at the very least, not predictably.

Finally, his eyes landed back on the corner of angel’s-blue fabric extending from the pillow. Sitting down on the bed, he freed Emma’s nightshirt and brought it to his face. The wool was worn and soft and smelled of vanilla and sandalwood. A wave of sensations washed over him. The feel of the firm, rounded muscles that ran the length of her spine. The warmth that radiated from the base of her neck. The desire sparked by her coy smile peeking up at him from beneath the spray of hair.

“Yes?” Emma would say, drawing out the word like a dare.

Jonathan lowered the nightshirt to his lap. All that was gone. A current of longing seized him. A current so powerful that it threatened to grow into a panic. Panic at his permanent, inconsolable loss.

He looked at Emma’s nightshirt and breathed easier. He was not ready to say goodbye. He folded it up and replaced it under the pillow. For a while yet, he wanted to keep her with him.

The headquarters of the Service for Analysis and Prevention was located in a modern steel-and-glass building on the Nussbaumstrasse in Bern. The staff of the Swiss counterespionage service numbered fewer than two hundred souls. Their tasks were geared primarily toward information collection and analysis, and involved keeping tabs on registered agents of foreign governments, most of whom resided in Bern, and monitoring what it regarded as clandestine communications traffic in and out of the country. Only thirty officers were assigned to more active work-that is, the day-to-day investigation and infiltration of extremist groups operating on Swiss soil, including foreign terrorist cells. In every sense it was a small, tightly run operation.

Marcus von Daniken arrived at seven sharp and set to work. Picking up the phone, he dialed an internal number. A woman answered. “Schmid. ISIS.”

Von Daniken identified himself. “I need everything we have on a subject on our watch list named Theo Lammers. It’s urgent.”

“Yes, sir. I’ll send it right away.”

A minute later, a chime rang from his computer indicating a newly arrived e-mail. Von Daniken was pleased to see that it was the file from ISIS. The report was a summary of information passed along by the Belgian police.

Theodoor Albrecht Lammers was born in Rotterdam in 1961. After earning a doctorate in mechanical engineering at Utrecht University, he drifted in and out of jobs at several undistinguished firms in Amsterdam and The Hague. He came to the notice of the authorities in 1987 while working in Brussels as an associate of Gerald Bull, the American armaments designer. At the time, Bull was busy creating a “supergun” for Saddam Hussein. Code-named Babylon, the gun was actually a giant artillery piece capable of lobbing a shell hundreds of miles with deadly accuracy. His work for the Middle Eastern potentate was a matter of public record. All the same, Bull and his associates (Theo Lammers included) were considered “persons of interest” by the Belgian police.

Von Daniken knew the rest of the story himself. Gerald Bull was murdered in 1990, shot five times in the back of the head by an assassin waiting in the foyer of his Brussels apartment. At first, speculation had it that it was the Mossad, Israel’s intelligence service, which had killed him. The speculation was incorrect. At the time, the Israelis had kept up a distant but cordial relationship with the scientist. As prospective clients, they were eager to know exactly what he was up to. It was for this very reason that the Iraqis had killed him. Once the Babylon gun was built, Saddam Hussein did not want Bull sharing its secrets with anyone, especially the Israelis.

Von Daniken closed the e-mail, then stood and walked to the window. The morning was gray and grim, wet snow dropping from lowlying cloud cover. The view gave onto a parking lot, and farther on, a half-finished office tower, crawling with laborers despite the weather.

And Lammers? he asked himself. What had he been up to that warranted keeping an Uzi in his workshop and a variety of passports in his bathroom? Or to necessitate sending a professional killer to lie in wait behind his woodshed?

Von Daniken returned to his desk. Several dossiers lay on top. They were labeled “Airports and Immigration,” “Counterterrorism/Domestic,” “Counterterrorism/Foreign,” and “Trafficking.” He skimmed their contents, saving “Counterterrorism/Foreign” for last.

This dossier contained a summary of wires from foreign security services. In 1971, the chief of the Swiss intelligence service, alarmed by the specter of politically motivated acts of violence, helped establish a confederation of Western European law enforcement professionals charged with ensuring their country’s internal security. The group became known as the Club of Bern. After 9/11, the group formalized their relationship and took the name “Counterterror Group,” or CTG.