Nothing left to save, he thought.

  In his backseat, Langdon and Solomon had fallen into a stunned silence after glimpsing the extent of the devastation they had survived. All that was left of the Folimanka bomb shelter was a gaping hollow, several stories deep, filled with a jumble of rocks, earth, shattered concrete, and twisted steel.

  Kerble could not imagine what had caused the unusual explosion. As far as he could tell, there had been no fire or heat—only cold. He knew the Soviet-era bomb shelter had been under restoration by the U.S. Army Corps of Engineers for the past couple of years, and it certainly should not have contained any explosives.

  “Where are you taking us?” Langdon asked from the backseat.

  Good question, Kerble thought. He hadn’t quite worked out the big picture, but he knew Ambassador Nagel and CIA Director Judd were locked in a power struggle, and it somehow involved Langdon and Solomon.

  After the blast, as Kerble hurried down the ridge, he had phoned Nagel to confirm her safety. She had been on a call with the director. When Kerble explained that the tremor was not an earthquake but rather an explosion beneath Folimanka Park, Nagel’s first words, strangely, had been to inquire about Langdon and Solomon’s whereabouts. She ordered Kerble to head to the scene and search for them.

  Regardless of what was unfolding between the ambassador and the CIA director, Kerble had already chosen sides an hour ago, with his snap decision to smuggle Nagel’s diplomatic pouch out of the embassy. It was a timely improvisation, as the director had almost immediately ordered a search of the ambassadorial suite along with her closest staff, including Kerble himself.

  If I’d kept the pouch…the CIA would have it now.

  As he drove toward the embassy, in case his sedan was being tracked, Kerble’s instincts told him that delivering Langdon and Solomon into the hands of the CIA director was not what Nagel would want. He also sensed there was a lot he was not being told by the Americans in the backseat.

  “We need to get out,” Langdon declared, his voice surprisingly authoritative considering the circumstances. “I can’t give you details, but trust me when I tell you that your ambassador is in grave danger—especially if the CIA director has detained her.”

  Grave danger? Kerble was well aware of Gregory Judd’s reputation for taking no prisoners when it came to national security. But would he really harm an ambassador? Kerble considered mentioning the diplomatic pouch that the director had seemed intent on finding, but the ambassador’s orders about the pouch had been clear. Tell no one.

  “If the ambassador is going to survive this—physically or politically,” Langdon said, “I believe there is only one thing left that can help her. I also believe I can find it.”

  Despite the boldness of the claim, Kerble sensed the man at least believed what he was saying. “What is it you’re looking for?”

  “It’s not a what,” Langdon replied. “It’s a whom.”

  Kerble glanced up, locking eyes with the professor in the rearview mirror. “Who is it?”

  “Her name is Sasha Vesna,” Langdon said, “and everything the ambassador needs to weather this storm is located in Sasha’s head.”

  Robert knows how to find Sasha?

  For a moment, Katherine feared Langdon might be bluffing, but his nod of assurance told her he was speaking in earnest.

  Finding Sasha is the key to everything…

  Far more conclusive than the binder Katherine had lost in the blast, Sasha herself was the most irrefutable proof that Threshold had even existed. A single brain scan would prove not only that this advanced implant was real, but also that the CIA had tricked a young Russian psychiatric patient into becoming a medical test subject.

  Locating Sasha was even more important now, as the destruction of Threshold had made their tenuous situation even more dangerous. The CIA would be in damage-control mode, and with all evidence of wrongdoing conveniently buried beneath Folimanka Park, the agency would be moving quickly to tie up all loose ends.

  Robert and I definitely qualify as unresolved details, she knew. As do Sasha Vesna and Dmitri Sysevich.

  Katherine pictured the eerily cloaked figure they had seen in Threshold. The man had proclaimed himself “Sasha’s protector” and was almost certainly Sysevich—the dark-haired Russian epileptic who, like Sasha, had been taken from an institution. His medical records, at first glance, had suggested to Katherine that he had died, but it now appeared something else had happened to him. Perhaps he had escaped their grasp. Whatever his situation, nobody more than Dmitri possessed the motivation to return and obliterate the facility that had subjected him to untold horrors.

  Mental illness, Katherine suspected, was almost certainly involved. The man smeared himself with clay and sacrificed his life to destroy Threshold. She wondered if Dmitri had a preexisting psychological condition in the institution, or whether it had been caused by the trauma of invasive brain surgery and forced psychedelic drug use. Either way, Dmitri Sysevich was clearly not a well man.

  Sasha is somewhere safe, the man had said.

  “Robert,” Katherine urged. “You really know where to find Sasha?”

  “I just figured it out,” he replied. “There’s only one place she could be…but in order to find her, I need to get into her apartment—”

  “She’s not there,” Kerble interrupted. “I was the one who found Harris’s body. Sasha was long gone. Our team quickly retrieved Harris, locked up, and left.”

  “I understand,” Langdon said. “But I still need to get inside. There’s something there that can help us. How did you gain access to her apartment?”

  “My colleague, Dana Daněk. She had a key.”

  “On a Krazy Kitten key ring?” Langdon asked.

  Kerble glanced over his shoulder. “How did you know that?”

  “Because I’m the one who gave it to Ms. Daněk. And now I need it back from her immediately.”

  “That’s impossible,” Kerble said. “Dana no longer has it.”

  Langdon cursed under his breath. “Who has it now?”

  Kerble reached into his pocket and tossed a small object back to Langdon. “You do, Professor.”

  A massive explosion in Prague?!

  Jonas Faukman frantically skimmed the New York Times alert on his computer and tried to convince himself that the blast was just a coincidence. Despite the statistical improbability that Langdon had been anywhere near the blast, his friend had a disconcerting habit of finding himself at the epicenter of trouble.

  More than an hour had passed since Langdon’s email, and there had been no word since then. Unable to push the mounting concern from his mind, Faukman dialed the Four Seasons Hotel in Prague and asked to be put through to Langdon’s room.

  Trudging through total darkness in the enclosed tunnel, The Golěm heard a sudden change in the reverberant sound of his footsteps.

  Less echo…I’m in an open space.

  Running his hand up the wall, he found a ledge and realized to his relief that he had finally reached the tram platform beneath Crucifix Bastion. The ledge was at eye level, higher than anticipated, and he would need to hoist himself up.

  He quickly shed his heavy cape and platform boots, arranging them in a pile at his feet. Then he stepped onto his makeshift stool, reached up, and felt the ledge, gauging its height. He would need to jump high enough to brace his elbows and forearms on the platform.

  You must escape. Sasha’s life depends on it.

  Fueled by the thought of her, The Golěm crouched low and leaped with all his strength, barely managing to prop himself up. Kicking his weary legs, he was able to swing one upward and hook his heel on the ledge. Fighting gravity and exhaustion, he dragged himself onto the metal platform…and collapsed.

  For nearly a full minute, he rested, eyes closed, breathing deeply.

  When he finally opened his eyes, The Golěm saw something hovering in the darkness…a tiny glowing circle.

  A light at the end of the tunnel.

  It was the illuminated button for the Crucifix Bastion elevator.

  CHAPTER 120

  Katherine felt wary as she and Langdon climbed out of the embassy sedan into the cold wind near Old Town Square. At Langdon’s request, Sergeant Kerble had agreed to deposit them here before he continued on to the embassy.

  I hope Robert knows what he’s doing.

  Over the past several minutes, she could tell Langdon was being strangely elusive with the Marine, refusing to reveal exactly where he believed Sasha was located. All he would say was that he needed to go to Sasha’s apartment to locate something that would help. Kerble seemed to understand, perhaps even appreciate, Langdon’s rationale for reticence. The CIA director desperately needs to locate Sasha Vesna; if questioned, Kerble can’t reveal what he doesn’t know.

  Katherine would have felt safer if Kerble had accompanied them, but clearly he needed to get back to the embassy. It seemed as if he might be the ambassador’s lone ally and felt obligated to be on-site to protect her from the CIA director in whatever way he could.

  “The ambassador will be grateful for your efforts,” Kerble said, rolling down his window to say a quick goodbye. “Good luck. Wherever it is you’re going.”

  “Thanks for your understanding,” Langdon replied.

  “OPSEC compartmentalization,” Kerble said. “You could be a Marine.”

  “There’s a scary thought,” Langdon said as he reached through the window and shook the Marine’s hand. “I’ve got your direct number. I’ll call you the second we have anything.”

  “If we locate Sasha,” Katherine added, “we’ll take her somewhere safe, and the ambassador will have all the leverage she needs to protect you.”

  “I hope you’re right,” Kerble said. “Court-martials have a way of ruining a weekend.”

  As the Marine pulled away, Langdon put an arm around Katherine and guided her across the bustling square. On the far side, they passed beneath an archway into a series of narrow alleys. When the sounds of the square began fading behind them, Katherine sensed it was finally private enough to talk.

  “So what’s going on?” she blurted. “And where are we going? Where is Sasha?”

  “We’re going to her apartment,” he said. “I figured out that Sasha never left. She couldn’t have. She’s still inside.”

  Katherine stopped short. “That Marine just said Sasha is not there.”

  “He’s wrong.”

  “He said forensics searched the apartment!”

  “Yes, but they didn’t search the whole thing.”

  “I don’t understand.”

  “You will,” he said, holding out his hand. “Come on.”

  Katherine followed Langdon deeper into the maze of alleyways surrounding Prague’s town square. I’m glad he has a good memory, she thought as he retraced the path that Sasha had taken him on earlier today. The alleys grew even narrower, and the cobblestone walkways fell into dark shadows with the fading afternoon light.

  “This is it,” Langdon finally announced, stopping outside a nondescript door that looked like every other doorway they had passed.

  “You’re certain?” Katherine saw no numbers or markings.

  Langdon pointed to the window beside the door, and Katherine was startled to see four eyes staring out at her. Two Siamese cats watched intently from inside, as if awaiting their owner’s return. Despite confirming this was Sasha’s apartment, the presence of her cats only furthered Katherine’s mystification as to why Langdon thought Sasha was actually here. “Robert, those cats look like they’re waiting for Sasha to get home.”

  “They are,” Langdon said. “They just don’t know she’s here either.”

  The comment made no sense to Katherine.

  “Look at this alley,” Langdon said, motioning around them. “Remember I told you about the note that was slipped under Sasha’s door this morning? Within seconds of getting the note, I ran out into this very alleyway, but the messenger had vanished. Impossibly so. He couldn’t have simply disappeared into thin air.”

  She surveyed the alley. Admittedly, nowhere to hide.

  “And then I realized,” Langdon said, “the answer was obvious. The person who left the note…never fled the area. He simply stepped into a very convenient hiding place.”

  Katherine glanced around, confused. “Where?”

  “Right there,” Langdon said, pointing.

  Katherine’s gaze followed Langdon’s outstretched finger up the facade of the building to a set of windows directly above Sasha’s apartment. All of the upstairs windows were boarded up with heavy wooden shutters.

  “The apartment upstairs,” Langdon said. “Gessner said she owns both flats and used to live up there over her ailing mother. Now she lets Sasha use the lower apartment, and the upper apartment sits…vacant.”

  Katherine studied the shuttered windows of the empty flat and pictured someone—most likely Dmitri—placing a note under Sasha’s door and then quietly slipping upstairs while Langdon searched the street in vain. Quite possible…

  Langdon strode to the building’s outer door, which was made of thick wood, diagonally slatted, with a security screen. He fished the Krazy Kitten key ring from his pocket, unlocked the door, and ushered Katherine into the dingy foyer.

  Despite the modest entrance, she could see that Sasha had made it her home. Her apartment door was immediately on the right, decorated with potted plants, a wisteria wreath, and a welcome mat that said: PLEASE WIPE YOUR PAWS.

  On the back wall of the foyer, a small storage room was packed to the ceiling with old cardboard boxes. To Katherine’s surprise, Langdon headed directly for it, stopping only an inch from the blockade of boxes, his chest practically touching them. He peered upward, as if studying the architecture of the alcove, and then gave a nod, waving her over.

  As Katherine approached, Langdon stepped sideways to his right, disappearing into an imperceptible opening that apparently existed between the boxes and the wall of the alcove. Startled, she quickly followed, slipping through the cramped passageway, turning left around the stack of boxes, then left again, finding herself at Langdon’s side. In the faint light filtering around the boxes, she could see that they were standing at the bottom of a narrow staircase, which ascended into darkness.

  This is not a storage room at all, she realized. It’s the landing to a staircase.

  “I didn’t notice initially that this foyer had no staircase to the second floor. Later, I realized there had to be access, and since there’s no separate entrance, both apartments would have to be accessible through this foyer. It also explains how someone could disappear without a trace immediately after sliding a note under Sasha’s door.”

  Katherine nodded. “Hiding just a few steps away. Very clever.”

  “Yes, and after I ran off to Petřín Tower, he simply emerged from hiding, entered Sasha’s apartment, and either convinced her to go upstairs or incapacitated her somehow. Either way, he must have left her upstairs so she wouldn’t have to see him killing Harris.”

  Simple and clean. Katherine nodded. “And when the embassy found Harris’s body, Sasha was gone, so they logically assumed she had fled the scene.”

  “Exactly.”

  “So how are you going to get into the apartment?” she asked, peering up the stairs.

  “I’m going to bang on the door and hope Sasha hears me.”

  “That’s your plan?” Katherine demanded. “What if she’s too drugged to hear you? Or she’s restrained and can’t get to the door?”

  Langdon frowned. “Then I have a plan B.”

  As Langdon started up the darkened staircase, he flipped the light switch at the bottom, but nothing happened.

  Katherine motioned to the fixture overhead, which was bare. “No bulb.”

  She was about to suggest Langdon go into Sasha’s apartment and find a flashlight, but he was already pushing on into the blackness, no doubt eager to get out of the cramped passageway.

  Katherine enjoyed darkness about as much as Langdon enjoyed enclosed spaces, but she forced herself to follow. With her hand placed firmly on the rickety railing, she climbed to the top of the stairs and reached out tentatively to find Langdon on the small landing, in near-complete darkness, standing outside a solitary door.

  “Sasha?!” he called, knocking. “Hello?!”

  Silence.

  He knocked more heavily now. “Sasha? It’s Robert Langdon! Are you okay?”

  Nothing.

  Langdon tried the door. Locked.

  After pounding some more, he held his ear to the door for a full ten seconds. Finally, he backed away and shook his head. “It’s dead quiet in there. I hope she’s okay.”

  “What was plan B?” Katherine asked in the darkness. “Should we find a crowbar or hammer?”

  “It might be simpler than that,” Langdon said, thinking. “Gessner owns both these apartments, and she used to live above her sick mother…” He seemed to be examining the door handle in the darkness.

  Katherine squinted to see what he was doing. “Are you trying to pick the lock?”

  “Not quite,” he replied. He continued to jiggle his hands, and then she heard the sound of a cylinder click. Langdon lifted the handle and gave the door a gentle push. It swung open.

  Katherine stared at him. “What just happened?”

  Langdon held up the Krazy Kitten key ring. “Gessner lived here, owned both apartments, and her mother was ailing—so why not make it simple and have one key that works for both flats, for easy access?”

  Of course, Katherine realized, and there was no reason to change the locks when Sasha moved in because the second apartment sat empty.

  As the door creaked inward, Langdon and Katherine found themselves staring into pitch-darkness, which was not surprising considering the heavy shutters shrouding the windows. Katherine reached inside the doorframe and felt around, locating a light switch. When she flipped it, they both stepped back in surprise. The scene that illuminated before them was a foreign world.

  The barren flat was bathed entirely in an eerie, purple luminescence.