“One thing I don’t understand,” Katherine said. “The brain implant…the neural mesh integrated so quickly—”

  “I’ve heard enough,” Langdon interrupted, eyeing Finch’s gun, still aimed at them both. “Sir, Katherine’s manuscript is destroyed. She’s not going to publish her book. We’re willing to sign your NDA. You can put the gun away.”

  “In due time,” Finch said, glancing over his shoulder at the doorway as if expecting someone. “I’m pleased that Dr. Solomon noticed we integrated her neural mesh so quickly.”

  Impossibly quickly, Katherine noted. According to the records they’d found, the rate at which Sasha’s existing neurons had fused with her artificial ones was ten times faster than natural growth patterns, or anything Katherine had seen in a lab setting.

  “The solution,” Finch boasted, “is a new technique we call ‘forced cooperation’—a kind of joint puzzle solving. We use virtual reality to feed the same puzzle into both the subject’s brain and also the implanted chip at the same time. As you know, when disconnected neurons sense they can be more efficient by sharing information, they form new synapses.”

  The most brilliant solutions are always the simplest, Katherine thought, and this strategy was exactly that—elegant in its simplicity. By presenting the identical challenge to two discrete processing machines—a human brain and a computer chip—they encouraged the two entities to cooperate…motivating them to synapse as quickly as possible. Neurons that fire together…wire together. The process was known as Hebbian learning, and it had been part of the neuroscience field since the 1930s when Donald Hebb discovered that the brain, when challenged repeatedly with intense tasks, would grow new neural pathways very quickly, in much the same way a weight lifter grew muscles by exercising.

  “And the drugs in the VR lab?” Katherine asked. “I assume psychedelics amplify neural plasticity?”

  “They do,” Finch said. “In addition to stimulating growth, the drugs are used to make the puzzles more challenging by forcing the brain to focus through a fog. It’s like a marathoner who trains in weighted sneakers. The added burden speeds up adaptation.”

  Katherine was amazed. “You didn’t get this idea from my thesis,” Katherine said. “Was it Brigita’s idea?”

  “Much of it, yes. She was not always easy, and we disagreed fundamentally on many things, but we couldn’t have built Threshold without her.”

  “Katherine’s thesis,” Langdon demanded. “How did the CIA have access to it?”

  “The Blavatnik Awards submissions,” he said. “Those submissions always contain the boldest ideas from the sharpest young minds. So back then the CIA always made sure that one of the judges was from Stanford Research Institute.”

  SRI? Katherine was amazed the connection had not occurred to her immediately upon learning of the CIA’s involvement in her missing manuscript. Stanford Research Institute had long-standing ties to the CIA and was even believed by conspiracy theorists to be the birthplace of Stargate. An SRI “professor” on the judges panel for the Blavatnik Awards could easily have been a spy hiding in plain sight.

  “When your thesis didn’t win even an honorable mention,” Finch said, “your Princeton professor—Cosgrove, I believe—questioned the prize committee relentlessly, especially the judge from Stanford. He figured out SRI was involved and knew enough to back off and never speak of it again.”

  “We want to leave,” Langdon said. “Now.”

  “You’re in no position to make demands, Professor,” Finch said. “You’ve broken into a top secret facility and violated many laws. And if you think the ambassador is going to come and save you, I doubt she is free to go anywhere at the moment.”

  “If Katherine and I disappear,” Langdon said, his tone threatening, “many people will notice. It won’t be like your anonymous test subject Sysevich.”

  “You know nothing of what happened to Dmitri.”

  “We know you used him as a human guinea pig,” Katherine said. “Along with Sasha Vesna.”

  “They were living tortured lives,” Finch fired back. “Gessner saved them. She cured their epilepsy and gave them a life.”

  “That’s your rationale?” Langdon challenged. “Does Dmitri have a better life now? We saw his records. It looks like he died here!”

  “Professor,” Finch said, shifting position and aiming the gun at Langdon now. “It must be luxurious to live in academia and not face the real problems in our country…not worry about those who want to destroy the Western way of life. The world is an extremely dangerous place, and people like me are the only reason your city of Boston is still standing. I mean that quite literally.”

  “That may be true,” Langdon replied, “but it doesn’t give you the right to experiment on human beings without their knowledge.”

  Finch stared at him. “The ultimate test of a man’s conscience is his willingness to sacrifice something today for future generations whose words of thanks will not be heard.”

  “If you’re going to steal a quote,” Langdon fired back, “you should know what it means. Gaylord Nelson was referring to saving the environment, not abusing innocent people.”

  “Sasha is far from innocent,” Finch said. “She murdered Dr. Gessner.”

  “That’s absurd,” Langdon said. “Sasha loved Brigita. There’s no—”

  “She also killed my field officer upstairs,” Finch said. “I half expected it was Sasha who had broken into Threshold. I found an epilepsy wand upstairs near my officer’s dead body…and there’s only one person it could belong to.”

  “That wand is mine,” declared a ghostly voice in the darkness. “And I want it back.”

  CHAPTER 115

  Finch whipped around in alarm and scanned the room.

  Who the hell said that?!

  The acoustics in the dome made it difficult to discern exactly where the words had come from. Langdon and Katherine looked equally startled.

  “Where are you?!” Finch called out, not recognizing the hollow male voice. The accent had definitely sounded Russian. “Show yourself now!”

  Finch heard a soft hiss of air, the only sound that pierced the silence of the dome. It was coming from the rear of the room, behind Langdon and Solomon. As his captives turned toward the sound, Finch looked past them, realizing this hiss was emanating from the pneumatic lift that accessed the utilities area.

  As the platform ascended, they all witnessed a spectacle unlike anything Finch would have imagined in his wildest dreams.

  From out of the earth…a monster was rising.

  The face appeared first—its skin deathly gray and featureless. The head was hairless, shrouded in the hood of a black cloak, and its two cold eyes seemed locked on Finch and his outstretched gun. As the cloaked body rose into view, its arms were extended horizontally, showing bare palms like some kind of ascendant Christ.

  When the pneumatic platform stopped, the figure stepped off and began moving toward them, his heavy boots thudding on the carpeted floor. Arms still splayed in surrender, he approached through the sea of pods, his black cloak billowing. Finch now saw that the monster’s head and face were caked with thick clay or mud, and some kind of writing was etched into his forehead. What the fuck is this thing?!

  “Stop!” Finch shouted, finally finding his voice when the creature was not more than fifteen yards away. “Not another step!”

  The monster obeyed, halting, his arms still outstretched.

  Finch stepped to his right for a clear shot past Langdon and Katherine. “Who are you?!” What are you?!

  “You have betrayed Sasha’s trust,” the figure replied, his voice hollow in the dome. “I am her protector.”

  “Is Sasha here too somewhere?” Finch demanded.

  “No, she is somewhere safe. She will never lay eyes on any of this again.”

  “And you are?”

  The monster’s body twitched suddenly, which seemed to startle him, but he regrouped. “I…am—” His voice cracked, and this time Finch saw fear flash in his eyes. The creature’s outstretched arms began trembling, and his defiant air evaporated. “No…ne seychas!” he stammered, his tone now more of a frightened supplication. “Not now…”

  Abruptly, the monster collapsed to the floor, his entire body shaking uncontrollably. He rolled onto his back, lying on the carpet, helpless, trembling.

  Finch had witnessed epileptic seizures before, and while he had no idea who this was, this person’s presence explained the epilepsy wand Finch had found upstairs. Is this another of Gessner’s patients? From outside the program?

  The monster was now struggling to search his cloak pockets, clearly trying in desperation to locate something.

  “Is this what you’re missing?” Finch taunted, pulling the metal wand from his pocket and moving toward the incapacitated figure. “Tell me who you are, and I’ll give this to you.”

  “He can’t speak!” Langdon shouted. “For God’s sake, help him!”

  “Would you like your wand?” Finch said, arriving over the figure, who convulsed helplessly, his head now vibrating against the floor.

  “Help him!” Katherine shouted.

  Gun still in hand, Finch crouched down beside the shuddering form and held the wand before his eyes. “Why don’t you start by telling me—”

  Finch never finished the sentence.

  In a flash of precisely coordinated movement, the trembling figure sat upright, and like a snake striking, one arm shot out toward Finch, connecting with his chest. There was a loud hiss and a flash of blue light, and a searing pain tore through the man’s body. Finch’s gun discharged into the side of a pod as he went rigid and fell forward, his attacker twisting deftly out of the way to allow Finch to hit the floor face-first.

  On impact, Finch felt the cartilage in his nose shatter completely. The pain was nauseating, like nothing he’d felt in his life. Blood streaming down his face, his paralyzed body came to rest on its side. He could see the cloaked figure rise effortlessly to his feet, a hand reaching down to collect the gun and wand, both of which Finch had dropped. The heavy platform boots moved toward Finch, inches away from his face. Gasping for breath, Finch strained to turn his head, his eyes climbing his attacker’s body all the way to his face. Upon seeing the monster who stood over him, Finch wondered if perhaps he had died and gone to hell.

  The creature staring down at him was barely human. His face was earthen with deep cracks running through his skin of dried clay. On his forehead, three symbols were etched deep into his muddy flesh. The creature’s eyes were unyielding, and their glare told Finch there would be no mercy.

  Robert Langdon was accustomed to processing complex information quickly. At the moment, however, the scene before him had unfolded too rapidly to comprehend fully what was happening. Finch now lay on the floor, quivering and debilitated. The cloaked figure facing Langdon and Katherine was wearing a costume of some sort; his shaved head and face were caked with thick clay, and his forehead was inscribed with a Hebrew word.

  אמת

  Langdon did not read Hebrew well, but these three letters were legendary. They spelled EMET, and when etched on a forehead, their meaning could never be mistaken.

  Truth…

  The Golěm of Prague.

  Before Langdon could even begin to try to make sense of any of it, the silence of the room was shattered by a deafening siren. Piercing and shrill, the alarm wailed overhead, and spinning warning lights began sweeping repeatedly around the interior of the dome.

  “Go!” shouted the figure in the cloak, pointing back the way they had come. “NOW! This entire facility is about to explode!”

  Langdon hoped he had heard incorrectly. Explode?!

  “We locked the RFID door!” Katherine said. “We have no card to get out!”

  “Come here!” The cloaked figure crouched down over Finch, who was still quivering, helpless. Langdon hurried over in bewilderment as the monster went through Finch’s pockets, pulled out his wallet, and extracted a black “PRAGUE” card identical to the one Gessner was carrying.

  “You’ll have twenty seconds,” the figure shouted, barely audible over the alarm as he grabbed Finch’s hand and forced the man’s thumb onto the surface of the card until a tiny indicator light turned green. He immediately handed the activated card to Langdon. “Twenty seconds! Go!”

  “What about you?!” Langdon asked.

  “I am The Golěm,” the figure replied. “I have died many times.”

  Godspeed, The Golěm thought, relieved to see Robert Langdon and Katherine Solomon racing from the dome. They do not deserve to die.

  Finch, however, was a different story.

  The Golěm stood over his bloody captive…the puppet master who had overseen this project. In the spinning lights of the Threshold dome, the creature turned to the nearest EPR pod, pressed the release button, and opened the lid. Then he hoisted the diminutive man up over the lip of the pod and dumped him inside as if he were already a lifeless corpse.

  Finch’s eyes bulged, and he started to regain mobility, but it was too late. The Golěm quickly affixed the pod’s heavy Velcro straps to his arms and legs, imprisoning his captive in the coffin-like interior.

  “Please…stop…” the man croaked, regaining his voice.

  Leaning into the pod, The Golěm placed his mouth an inch from Finch’s ear and whispered, “I wish I could turn your blood to ice and let you feel what I felt so many times…but there is no time for that.”

  “Who…are…you?” the man stammered.

  “You know me,” The Golěm replied. “You created me.”

  Finch stared up, scrutinizing his attacker, his eyes probing the monster’s face with increasing desperation. But The Golěm had no desire to give him the satisfaction of discovery.

  Calmly, The Golěm stared down at his victim and spoke the last words the man would ever hear. Then he pressed the button on the side of the pod and watched contentedly as the transparent gullwing lid lowered into place, sealing Finch inside, muting his screams of terror, which were lost in the siren’s urgent wail.

  CHAPTER 116

  Langdon and Katherine burst into the hallway outside the domed suite, having barely managed to unlock the RFID scanner with Finch’s card before it deactivated and blinked red in Langdon’s hand.

  In unison, they turned right, racing together toward stairs at the end of the hallway. It seemed a good bet that these stairs were a faster way out than the circuitous route by which they’d entered.

  In the chaotic flash of spinning security lights, they reached the door at the end of the hall and hurried into a drab concrete stairwell. Bounding up steps two at a time, Langdon could still hear the hollow voice of the clay-covered creature who had just helped them escape. This entire facility is about to explode. How or why that would happen, Langdon had no idea, but judging from the sirens and emergency lighting, something in Threshold had definitely gone catastrophically wrong—most likely by the man’s own hand.

  One of the by-products of fear, Langdon knew—especially the fear of death—was total clarity of purpose. Despite the tangle of questions in his head about what had just transpired in the dome, Langdon’s brain had muted that noise and tuned itself to one, solitary channel.

  Survival.

  He led the way to the upper landing, where he and Katherine arrived breathless at a metal door marked ADMIN. Without hesitation, Langdon pushed through, and they found themselves in a carpeted, oak-paneled corridor. Gone were the cold, sterile edges of the operations facility; this looked more like the corporate offices of a sophisticated Cambridge law firm.

  They ran down the hall, past conference rooms, offices, and into a sprawling cubicle farm. Here Katherine stopped short, reaching out and stopping Langdon as well. At the far end of the room, a professionally dressed woman was urgently gathering items off her cubicle. Apparently, Threshold had not been entirely deserted today. Just then, two young men in suits rushed over to join her, motioning for her to follow. They all ran off without looking back.

  Follow them, Langdon thought. They must know the way out.

  Once they were out of sight, Langdon and Katherine headed in their direction, which he suspected was toward the main entrance they had seen earlier on the edge of Folimanka Park. Langdon eyed the classified binder sticking out of Katherine’s shoulder bag and hoped the emergency evacuation would create enough chaos that they could slip away undetected.

  If we get out in time, he thought as the sirens wailed overhead.

  “There!” Katherine shouted, pointing to a glowing EXIT sign at the end of the hallway.

  They pushed through the doors and found themselves in a security room similar to the one they’d passed through earlier—with a metal detector, X-ray conveyer, and body scan. Fortunately, it was unmanned, and Langdon and Katherine rushed through, emerging into what appeared to be a large underground parking garage, mostly empty except for several construction vehicles, a few cars, and some large machinery on flatbeds.

  Fifty yards ahead, Langdon saw what he had feared they might never see again.

  Daylight.

  At the far end of the parking lot, the bunker’s arched opening led up the inclined driveway. The three employees they had just seen inside were now hurrying up the slope and disappearing from view. Langdon and Katherine ran toward the opening, but as they did, the daylight began to fade…the opening beginning to taper.

  They’re closing the door!

  “Wait!” Langdon shouted, his voice swallowed by the cacophony of alarms. “WAIT!”

  He could see they would never make it. Still twenty yards away, the shaft of daylight dwindled to a sliver and then disappeared entirely as the portal slid shut with a resounding thud, sealing them inside.

  Three stories below, strapped down like some violent psychiatric patient, Mr. Finch had stopped struggling. He could only stare upward in disbelief through the translucent cover of the EPR pod and watch the muted shapes of emergency lights sweeping across the dome above.