“The biggest consequence, however, was on sea currents. The flood of freshwater into the Northern Atlantic pushed back on the flow of warm water from the equator moving north. That warmer water was redirected south, toward Antarctica, shrinking the ice there and changing the circumpolar winds. In the course of a thousand years, most of the planet went from being a frozen wilderness to a fertile world perfect for our species. It was almost tailor-made for humans. We were alive at exactly the right time. And it changed us.

  “That was Kraus’s central theory. That the end of the last ice age kicked off a period of rapid evolution for our species. In the context of punctuated equilibrium, we call the splitting of a species ‘cladogenesis.’ Some scientists on the Beagle believed that the human race was splitting into two species, but the genetic evidence they gathered didn’t support that. Kraus posited that one tribe developed a substantial genetic advantage—and it centered on how their minds worked. Art is the evidence of that change.”

  Lin motioned to the cave. “That’s why he was so interested in this place. Altamira is one of the oldest examples of cave art and fictive thinking. Kraus believed that the advent of art was a transcendental moment in our evolution. He believed…” She glanced at the crates. “He believed it was like opening Pandora’s box. Fictive thinking triggered a further acceleration in human evolution. If you compare our progress in the last thirty-five thousand years with the millions of years hominids inhabited the planet before, it’s like we’re a completely different type of organism. To him, there had to be a reason for such a dramatic shift—an environmental factor driving the change in our behavior. But we could find no environmental factor.”

  “That’s why you needed the Beagle,” Nigel said. “To take ice core, archeological, and biological samples from around the world. In secret. You were trying to find evidence of environmental triggers in the past.”

  “Yes. Our first theory was HGT.”

  Nigel nodded.

  “Okay,” said Avery, “I’ll bite. What’s HGT?”

  “Horizontal gene transfer,” Lin said, “sometimes referred to as lateral gene transfer. Most of evolution occurs though vertical gene transfer—DNA being passed from parent to child. Horizontal transfer is when DNA is acquired from another living organism.”

  “It happens all the time in bacteria,” Nigel said. “One bacteria develops an advantage and transfers it to another. That’s how they become antibiotic resistant, among other things.”

  Lin nodded. “In our case, we thought perhaps there was some external source of DNA that was driving human evolution, almost like a symbiotic relationship—feeding us genes that advanced us.”

  “Like aliens?” Avery said, skeptical.

  “No, nothing that dramatic. We thought perhaps some symbiotic bacteria or virus in the gut. When Kraus looked at the long arc of history, he saw some very strange patterns. In particular, a certain synchronicity. Take these cave paintings, for instance.” She walked closer to the cave wall. “Cave paintings appeared at about the same time in multiple places in Europe and the Middle East. Why? How did fictive thinking—this evolutionary leap forward—occur almost simultaneously in independent populations separated by huge distances? The same thing happened with the development of agriculture, twelve thousand years ago. We found eleven different civilizations, completely isolated from each other, in which agriculture emerged independently, at almost exactly the same time. Or writing—the next great human breakthrough, as it allowed us to store data far more efficiently than we could through oral traditions. This, too, occurred at the same time, in at least three isolated groups.

  “To Kraus, this synchronicity was the ultimate evidence that there was an incredibly powerful force sculpting humanity. He called it the Invisible Sun. To him, evolution was like this cave, each chamber leading to another. Art, then farming, then writing—these are the three principal chambers humanity has passed through, and each has left a genetic mark. Kraus believed that the last chamber, a final great leap for humanity, was yet to come.”

  “The code,” Peyton said.

  “Exactly. Kraus believed that when we found the genetic bread crumbs left by the march of evolution, that they would form a code that could unlock the next great change in human existence—this one far more profound than art, farming, or writing.”

  “What is it?” Avery asked.

  “I don’t know. He didn’t either. And we didn’t have the technology back then. Human genome sequencing was impossible. And even once it was possible, it’s been cost-prohibitive until very recently.”

  “And now you’re ready,” Avery said. “You built Phaethon Genetics for just this moment. The recovery of these samples.”

  Lin studied the crates. “This moment is more important than any of you understand. The sacrifices that have been made. The giants whose shoulders we stand upon. We’re on the precipice of something incredible.”

  An awkward silence stretched out. In that hidden room, in the dim light, Lin Shaw seemed almost possessed.

  Boots pounded the cave floor. The makeshift door to the hidden room pushed in, and a hand forced it open wider.

  Rodriguez slid through the opening, followed by three SAS soldiers Peyton had never seen. Despite the chill in the cave, Rodriguez was sweating. And his gun was gone.

  “Ma’am,” he said. “We’re ready to load out.”

  Adams moved his head quickly, as if seeing something, then relaxed. Lin stared at him, then Rodriguez.

  Peyton sensed that something was wrong.

  To her surprise, her mother said, “Proceed, Corporal.”

  Chapter 44

  Peyton sensed a change happening in the room. It was as if one by one, the team was becoming aware of something—like prey learning that a predator was approaching. Lin appeared to realize first, then it moved like a wave to Adams and Avery. Nigel was muttering something, apparently unaware. Rodriguez was trying to communicate something to Adams with his eyes.

  The hidden room deep inside the Cave of Altamira was cramped, but the three SAS troops were doing their best to spread out.

  Suddenly, Lin slipped behind the closest SAS soldier. A split second later, Adams leapt on top of the operative beside him. Avery moved behind the last man, drawing a combat knife and placing it at his neck.

  The room fell silent. No one moved.

  Peyton realized her mother was holding a handgun at the back of the soldier’s neck.

  The man slowly let his hands drift out. “Ma’am,” he said in a British accent. “I think there’s been a misunderstanding—”

  “Don’t.” Lin’s voice echoed in the small space like a slap.

  A silent second passed.

  “The boots. I know they’re Citium Security issue.” To Peyton and Nigel, she said, “Take their weapons.”

  When they had taken their guns and knives and radios, Lin pushed at the back of the man’s neck, prodding him to join the other two. “Is he here?” she demanded.

  The man’s face was stone. “Can’t say I know who ‘he’ is.”

  “I’ll take that as a yes.”

  “Ma’am?” Adams said.

  “Yuri.” Then to Rodriguez: “Report, Corporal.”

  His eyes drifted down to the floor, a look of embarrassment and disappointment settling over him. “I hiked to the radio cutoff and requested backup to help with transport. The operator used the breach code word in his response.” He shook his head. “I turned and started running back, but they were already in the tunnel.” He swallowed. “I should have—”

  “Thank you, Corporal,” Lin said.

  Adams took out the cave map and pointed to a narrow passageway near the hidden room. “We’ll set up a chokepoint here.”

  “No,” Lin said. “We can’t fight our way out of here.”

  “Is there another exit?”

  “No. We’re trapped. And outgunned. And ill supplied for a siege. Those are the certainties.”

  Chapter 45

  Ad
ams inhaled and straightened, like a man who expected to soon face a firing squad. “What are your orders, ma’am?”

  Lin placed her gun on the nearest crate. Her voice was quiet. “I’ll handle this.”

  Nigel threw up his hands. “Oh, good. I feel relieved. Care to share any details? I’m particularly curious as to whether I will die in the process?”

  Lin ignored Nigel’s theatrics. She answered in a somber tone. “Unknown, Dr. Greene.”

  His eyes grew wide. “Well, what do you know?”

  “As I said, I know we’re trapped.”

  “Then what’s your plan?” Nigel spat.

  Avery’s voice reflected Lin’s calm. “Let’s talk options.”

  Lin affixed the top to the plastic container she and Peyton had found. “There are none. There is no play here. Our adversary is a strategist with no peers. If not for his work in the Citium, he would likely be the world’s leading expert in game theory. Any plan I can think of, he’s already considered.”

  The room fell silent, the reality sinking in.

  Peyton broke the silence. “Mom, when you said you’d handle this—”

  “I’ll go alone.”

  “No.” Peyton closed her eyes. Less than a month ago, Yuri had killed her father. And before that, Yuri had kidnapped her brother and brainwashed him. She couldn’t lose her mother too. “There has to be another way.”

  “There isn’t. Yuri is here for me. I’m the threat to his work. He needs to capture me. He needs me to tell him my plan, and who I’m working with. In exchange, I’ll ask for your freedom. At least for you all to be supplied and confined here until this… Looking Glass war is done.” She exhaled. “Once he has me, he’ll have no need for the rest of you.”

  “Exactly!” Nigel yelled. “He’ll kill us all.”

  “I doubt that—”

  “You doubt it?” Nigel turned to Adams. “This is clearly a military matter. Chief, we should be deferring to you. Please formulate—”

  “I don’t take orders from you, Doctor.” Adams focused on Lin. “Ma’am?”

  “When I leave, split up and hide. Rodriguez and these Citium operatives will accompany me—”

  “Don’t we need hostages?” Nigel asked, exasperated.

  “No,” Avery said, “we do not. We need to be able to fight, and we don’t have the kit to run an underground prison camp.”

  “We could lock them in here.”

  “And let them destroy what we just found? Stick to science, Doctor.” To Lin, Avery said, “Continue.”

  “Rodriguez will stay with one of the Citium operatives just inside the comm range. He’ll relay the result of my negotiation with Yuri.”

  “Negotiation,” Nigel muttered. “Surrender is more like it.”

  Lin ignored him. She stepped over to Peyton, gripped her shoulders, and looked her directly in the eyes, unblinking. “I love you very much.”

  Peyton was shocked. Her mother rarely showed affection, and never in front of others, especially anyone outside the family.

  A wall within Peyton broke. A tear formed at the corner of her eye and rolled down her face. In any other moment, she would have wiped it away, embarrassed, but now she let it slide down, like the last grain of sand falling through an hourglass, a symbol of her time with her mother, which might be up.

  Her voice was low and heavy with emotion. “I love you too.”

  Lin pulled her into a hug and held it. When she released Peyton, she walked to Adams, who stood straighter as she approached.

  Even in the silent cave chamber, Peyton could barely hear her mother’s voice. “Take care of my daughter, Chief. She is more important to me than anything in this room.”

  Peyton felt another tear escape her eye. And another. She avoided crying out loud, but just barely. Growing up, she had always come second to her mother’s work. Missed soccer games, birthday parties, family time. Even her medical school graduation. Lin Shaw’s work came first—and this room held the crowning achievement to that work. Lin Shaw had cajoled and killed and sacrificed for decades to find it. And now, in what might be the final chapter of her life, she had revealed what was truly important to her: Peyton.

  Like any child, Peyton had always wondered where she stood in her mother’s hierarchy of priorities. Now she knew, and it broke her heart all over again.

  Lin turned to the group. “Let’s proceed.”

  At the opening to the room, she paused but didn’t look back. “Wait twenty seconds, then split up and hide. Use the earpieces for your radio to keep quiet.”

  With that, she slipped through the opening, and Peyton wondered if she would ever see her mother again.

  The cave paintings danced at the edge of the lantern light, making the animals seem alive. Lin remembered walking into this cave with her father. Her fascination with his work had been born here that day. One way or another, she would complete her own journey to finish his quest today. But there was far more at stake than that.

  In front of her, the two Citium troops clad in SAS uniforms halted, one holding up a fisted hand. Lin and Rodriguez came to a stop, as did the other Citium mercenary behind them.

  Figures emerged from the shadows, their guns held out, bodies clad in black body armor, night vision goggles flipped up.

  “Sit-rep,” one of the black-clad operatives barked.

  “They’ve surrendered,” the SAS-clad operative said. “The woman wants to discuss terms with Pachenko.”

  Without a word, the mercenaries rushed to Lin and Rodriguez and frisked them.

  A mercenary motioned to the Navy SEAL. “What’s he doing here?”

  “For the comm relay. The others are hiding until they hear from her. Keep an eye on him.” The SAS-clad operative turned to Lin. “Let’s go.”

  The morning light spilling through the mouth of the cave was blinding. Lin paused to squeeze her eyes shut.

  She heard boots pounding the stone ahead, drawing closer.

  By degrees, she allowed her eyes to open. When the scene came into focus, she saw a dozen men crowding into the main chamber off the entrance, all wearing SAS or Spanish Army uniforms—except for the boots. No one had bothered to change out of the Citium-issued boots, perhaps for comfort, perhaps because finding the right fit would be like a massive game of musical chairs.

  The first troops they had met in the cave had apparently radioed ahead and apprised the units here of the situation. They waved Lin forward.

  Inside the visitor center, there was a stack of bodies—men and women in underwear—most with gunshot wounds to the torso. A still pool of blood encircled them, half in shadow, making it look black, like an oil spill. It was the most grotesque thing she had seen since the occupation of Hong Kong.

  “Hello, Lin.” Yuri’s voice was emotionless, as if there were no water under the bridge between them—and she wasn’t his prisoner.

  Lin tried to control her breathing. Her voice came out harder than she wanted, her emotions betraying her. “I’ve come to talk.”

  “Then I will listen.”

  “In private.”

  Yuri squinted, studying her face.

  Lin cleared her throat. “I’m willing to tell you what you want to know. Time is not on your side. That’s what I can give you. I want her safety. That’s all I want.”

  Yuri paused, then addressed the Citium operative who had brought Lin out of the cave. “Report, Captain.”

  “Yuri—”

  “Please be quiet, Lin.”

  She listened while the man recounted everything that had happened.

  Yuri appeared to think on this for a moment, then to another nearby soldier said, “Status on Bravo unit?”

  The man activated his radio and conversed before reporting: “No movement. Shaw’s SEAL hasn’t said or done anything.”

  Yuri frowned. “Search her.”

  Two men ran their hands over her body, poking and kneading, patting and rubbing, indelicate, degrading actions. She stared ahead, face burning, hatred
welling up. She had endured this before, but it had been a very long time. When it was done, the men said nothing, merely nodded to Yuri.

  “Well then. Let’s talk.”

  Yuri led her to a small office behind the information desk and closed the door behind them. Lin quickly took in the room, including all the items on the desk.

  “This reminds me of Rio. The favelas.”

  Yuri was silent.

  “We were prisoners then too. Held in a small room. Our bloody captors degrading us. The only difference now is that you’re the madman on the other side of the gun, Yuri.”

  Lin watched, hoping he would crack a little—or even react to the words. He didn’t.

  “It’s not too late to stop this.”

  A cold smile crossed Yuri’s lips. “We both know it is. There’s only one way forward for me. The Looking Glass has always been my only hope.” He stepped closer to her. “And I just got one of the last pieces I need.”

  “But you’re still missing one piece.” Lin let a moment pass. “Rendition. Desmond Hughes is the only factor you misjudged in all this. He’s different from you and Conner—more so than you realized. That must be hard for you.”

  “All’s well that ends well.” Yuri averted his eyes. “And besides, I have also recently acquired the key to controlling Desmond.” The smile returned. “Peyton. And perhaps Avery. I wasn’t here just for you.”