Changeling

TWENTY-THREE

The first thing Jade did when Professor stepped off the loading ramp of the United States Air Force C-130 Globemaster cargo plane was run up to him and tug his cheek to make sure that it was really him and not someone wearing a mask.

The second thing she did was kiss him.

He did not resist. Jade was pretty sure that he was enjoying the display of affection, but she also knew he would never let her live it down, so as she pulled away she said, “Just needed to do that for future reference.”

“I missed you, too,” he said. “Future reference?”

“There are some things a Changeling can’t duplicate.”

“Eww. Don’t tell me you kissed… You know what, I don’t want to know.” He threw his arms around her and hugged her. “God, what a nightmare that was.”

“You can tell me about it on the way.” She took a step back and gestured to the man standing a few steps behind her. “Professor, meet Atash Shah.”

Professor regarded Shah suspiciously then extended his hand. Shah accepted the hand clasp, then went rigid, the blood draining from his face, as Professor squeezed.

“I appreciate what you did for Jade,” Professor said in a low voice, “but let me be clear. I think you are a terrorist—”

Jade put a hand on Professor’s chest and gave him a hard shove. “Knock it off. You would probably be dead if it wasn’t for him and his terrorists, so give it a rest.”

Shah however seemed oddly pleased by Professor’s display. “That’s okay. I’m rather used to that sort of ignorant prejudice.”

“Ignorant?” There was strange gleam in Professor’s eyes. “I guess I have more experience with your so-called ‘religion of peace’ than you realize. Not as much as the friends I’ve buried, mind you—”

“Hey!” Jade said sharply. “Enough!”

Professor offered a tight smile then let go of Shah’s hand. “Looking forward to working with you.”

“So much for the happy reunion,” Jade growled under her breath. “I hope you got that out of your system. We’ve got work to do.”

“Something I have to take care of first.” He looked past her, settling his gaze on a convoy of black vans rolling toward the flight line.

Jade’s forehead drew into a crease. “You told someone you were coming here?”

Professor’s travel arrangements — hers and Shah’s too — had been shrouded in secrecy. With no way of knowing who could be trusted, it had been necessary to create several different itineraries and modes of travel, with multiple decoy destinations, and even then, there was no way of knowing if they had covered all their bases.

“Tam sent them. Of course I told her. Who do you think set everything up?”

“Well what are they doing here?”

“I brought Tam a souvenir.” He waved to someone in the interior of the aircraft, and two people emerged, moving slowly down the metal deck. One was a tall, muscly guy, wearing jeans, a Harley Davidson T-shirt and cowboy boots. Jade thought the second person might be a woman, but it was hard to tell for certain since she wore a shapeless orange prison jumpsuit with a high-collared bullet-proof vest and a burlap sack over her head.

“Whoa. You caught a live one?” Although they had spoken several times over the phone to coordinate this rendezvous, there had not been time to catch up on the details of their respective misadventures. Jade knew only that Professor had been imprisoned by the Changelings and had eventually escaped on his own.

“The big guy there is Billy Sievers, one of Tam’s new hires. He rode with me from Sydney. I guess as the low man on the totem pole, he got stuck with escort duty.”

“I do have some experience with it,” Sievers said in a deep Texas drawl.

“Used to work for an escort service, yeah?” Jade asked with a mischievous smile.

Seivers winked. “Wouldn’t you like to know?”

Jade turned her grin on Professor. “He’s cute. Let’s keep him.”

“Sorry, ma’am. I’ve already got a date.” Sievers gestured to the prisoner. “Not sure where I’m takin’ her yet, but it’s bound to be a good time. For one of us anyway.”

There was a hint of menace in his tone, and Jade decided that maybe Sievers wasn’t so cute after all.

The vans rolled up close to the cargo doors, forming a tight horseshoe with no gaps through which an observer might be able to see what was happening inside. Each of the vehicles opened, disgorging a contingent of men in army uniforms — the combat variety, replete with body armor, helmets, and assault rifles. They took up defensive positions all around the inner perimeter, as if anticipating an immediate attack.

Sievers turned to the prisoner. “Our ride’s here, honey.”

The woman did not respond to the sound of his voice but at a none-too-gentle nudge from Seivers, she began walking straight ahead. He guided her toward the second van in the line and then helped her step up into the vehicle. When she was back inside, he raised a hand to his forehead as if tipping the brim of an imaginary hat to Jade. “See you round, darlin’.”

Jade smiled, but muttered under her breath. “Not if I see you first.”

The soldiers broke formation and piled back into the vans. When they were gone, Jade gestured to the waiting rental car that would bear the three of them away. Once inside, with Jade behind the wheel, Professor riding shotgun and an eerily quiet Shah in the back seat, she asked, “Where will they take her?”

“A black site. A secret detention facility for enemies of the state too dangerous to be put into the criminal justice system.”

“Isn’t that illegal? Especially on American soil.”

“She’s one of them,” Professor said. “A Changeling. Leaving aside the fact that she deserves anything we could do to her, she’s part of a conspiracy that runs so deep, there’s no way of knowing who in our government is already compromised. Tam is going to play this very close to the vest. It’s the only way to root out the Changeling infiltrators.”

As Jade drove off the tarmac and navigated roads leading out of the base, Professor launched into a quick recap of everything that had happened, beginning with his capture in Sydney and ending with the crash on the Murchison Highway, a few miles outside of a remote Tasmanian mining town called Rosebery. When he told her about the uncertain but almost certainly terrible fate of the passengers on Flight 815, Jade was a little less inclined to worry about the prisoner’s civil liberties. If even half of what the woman — Eve — had revealed was true, then she and her Changeling brethren were beyond the reach of ordinary justice.

Jade almost interrupted Professor when he recounted his conversation with Eve regarding the Changelings’ true objective, but managed to contain herself until he finished his story, just as Jade turned east onto California state highway 58.

“There’s no trace of them now?” she asked.

“None. The fire is being investigated as a possible arson but it will be weeks before anyone can get in there to sift through the ashes. They covered their tracks pretty well. The investigator I met in Sydney, Sousa, supposedly went missing when the search plane he was riding in went down in the Pacific. According to the news reports, I was on that plane, too.”

“Wow. So you’re officially dead?”

“Officially missing,” he corrected, then added in a somber tone. “Like Flight 815.” He looked away, staring out at the barren landscape outside the car. “Where are we going?”

“The Vault,” she announced triumphantly, grateful for a chance to change to topic and share her discoveries. “It’s not what Roche thought it was.”

He returned a blank look.

“I sent you a text about this.”

“Somebody stole my phone, remember?”

“Oh, right.” She launched into her own account of recent doings, carefully glossing over the repeated attacks by Shah and his minions, focusing instead on what they had discovered with each successive stop along the way. When she mentioned infrasound, and related what had happened in the underground chamber in Peru, Professor sat up straighter. “You should have told me about that.”

She frowned. “You were supposed to tell me how clever I was for figuring it out on my own.”

“Well, obviously. But you shouldn’t keep things like that to yourself. I could have helped you figure it out.”

“At the time, I didn’t know what was happening. I only put it all together when we went to the Hypogeum.”

Professor rubbed his chin thoughtfully. “The chamber in Paracas and the Hypogeum have two things in common. Unusual acoustic properties and deformed skulls.”

“You think there’s a connection?”

“Let’s just say I don’t buy into Roche’s theory about artificial cranial deformation as a defense against the Changelings. But it would be interesting to compare the frequency shifts in a regular round human skull versus a flattened one.”

“Flat skulls can pick up more channels?”

“Actually, I was thinking the opposite. A lifetime in close proximity to those resonance chambers would probably drive an ordinary person insane.”

Jade grinned at him. “I’m so glad you’re back.”

He looked askance at her. “I’ll just pretend you really mean that.”

“Of course I meant it.”

“And still not convinced. So, what did you find at the Hypogeum?”

“God, it was incredible. Way more than just seeing ghosts. I had an out-of-body experience. I flew up into space, went halfway around the world, and then landed at the vault. I actually saw the lock mechanism that Archimedes described.”

“And was it a timelock like Roche said?”

Jade shrugged. “It was like looking at an electrical schematic. I can tell what it is, but I have no idea what it means or how it works.”

“Could you draw it from memory?”

“Possibly. There’s one thing I remember vividly. It was the last thing I saw before…” Her eye found Shah in the rear view mirror. “Before the vision ended. Three circles. They looked like they were linked, sort of like the Olympic rings, but they weren’t really. It was just an optical illusion.”

“Sounds like Borromean Rings.”

“Is that a Tolkien thing?”

Professor laughed. “Not quite. It’s a math problem. Complex geometry. It would be easier to show it than try to explain it. Got any paper?”

Jade took a notepad and the stub of a pencil from her shirt pocket, and passed it over. Professor flipped through page after page of sketches and field notes until he found a blank page. He spent a few minutes drawing a figure, then held it up to show her.

“That’s it,” she confirmed.

“Borromean Rings,” he confirmed. “They appear to be linked at the center, but when you follow the individual circles, you see that they’re actually sitting on top of each other, which is physically impossible. Well, with true circles anyway. You’ve never seen anything like this before?”

“Don’t think so. Archimedes was a math guy, yeah? Would he have known about them?”

“They don’t show up in the historical record until the 6th century, almost eight hundred years after Archimedes, but he was a genius. Way ahead of his time. And most of his writings have been lost. I wouldn’t be at all surprised if he at least toyed with the idea.” He stared at his sketch for a moment. “You know, according to most accounts, Archimedes was working on a problem right before he died. Supposedly, his last words were, ‘Don’t disturb my circles.’ Something to that effect. Maybe he was trying to solve the riddle of Borromean Rings.”

“Well, that was the last thing I saw. I think it’s important. Maybe the key to opening the vault.”

He nodded, then looked at her with the same suspicious glance. “Wait a second. You said we were going to the vault. But we’re driving toward Death Valley. Don’t tell me…”

“I saw where it is. In my vision.”

“And it’s in California?”

“Arizona, actually.”

He shook his head. “No. This is crazy. You had a bad trip, Jade. Infrasound stimulates different parts of the brain, but it can’t put ideas in your head that aren’t already there.”

“Why not? When you hear a song on the radio, it’s just a bunch of high frequency radio waves assembled a certain way. Maybe the ancients who built the Hypogeum built it so that it would play a specific pattern of resonance waves, to produce a specific effect.”

“Jade, think about it. You’ve done most of your work in the Southwest. Of course that’s what you would see. It’s just your brain trying to make sense of it.”

“If you had been there, you’d know that it wasn’t a hallucination. But it doesn’t matter. We’ll be there in a few hours. If we find it right where I saw it in my vision, then we’ll know I’m right. If it’s not there, I’ll admit I was wrong. Does that work for you?”

“If I may,” Shah said, breaking his long silence. “The Hypogeum is important. My partner knew that Jade would go there, and I think she knew what you would find.”

Professor craned his head around and stared at Shah. “Why is he here, again?”

“That was part of the deal for saving your ass,” Jade said. “I made the call. Get over it.”

He frowned but did not push the issue. “I’m still pretty skeptical about the role of infrasound in this, but I’ll allow for the possibility. We’ve seen too much crazy stuff to dismiss it out of hand. And like you said, if it’s not there, we’ll know. But has it occurred to you that, if it really is there, the Changelings know about it and will probably be waiting for you?”

“Which is why I’m glad that you’re back. One of the reasons, anyway.”

“So where is it? Exactly, I mean.”

Jade glanced at Shah again. She had not revealed the exact location to him or anyone else yet. But Professor was right. The Changelings weren’t looking for the vault. They almost certainly knew where it was. They were only interested in keeping anyone else from finding it. She was keeping the secret only to keep Shah from trying to double-cross her. Even a few hours’ advance notice would be enough for him to set up an ambush. But if that was his plan, then he would not make his move until the door to the vault was open, if it could be opened. She would only know his true intentions then.

“The Vault,” she said, “is in Sedona.”

TWENTY-FOUR

Although he initially greeted Jade’s declaration much the same way that he might have reacted to Jeremiah Stillman or someone of his ilk going on about extraterrestrial astronauts — for very nearly the same reason — he had to admit that it made a lot of sense.

The area surrounding the northern Arizona town — equal parts artists’ colony and tourist trap — situated about halfway between the city of Phoenix and the Grand Canyon, was renowned for a wide range of paranormal activities ranging from frequent UFO sightings to energy vortices capable of transporting people to parallel dimensions. The sheer volume of anecdotal evidence suggested that something might actually be happening at Sedona. There were simply too many stories to discount them all as cynical hoaxes or delusions brought on by too much time in the hot desert sun and unrealistic expectations.

The actual scientific evidence for such phenomena was sketchy. Pictures purporting to show auras and other ghostly images were easily dismissed as lens flares, or more often than not, were the result of hucksters using techniques like Kirlian photography to produce visually stunning, but definitely not supernatural images of electromagnetic fields. Terrestrial electromagnetic energy was widely cited as the source of Sedona’s strange phenomena. The area was reputed to be a major junction of electromagnetic meridians, often called “ley lines”—similar effects were often reported at the Pyramids of Egypt, Stonehenge, Easter Island, or anywhere that New Age gurus might be able to convince the gullible to part with their money — but EM effects could be measured, and there was no observable difference in the earth’s magnetic field at Sedona to back up this pseudo-scientific explanation.

Nevertheless, Jade’s experiences in Paracas and the Hypogeum had convinced him to give those stories a second look. In almost every case, the effects described by visitors to Sedona and the surrounding area mirrored the effects described in infrasound experiments, ranging from altered mood to hallucinations to temporary loss of consciousness and lapses of memory, which could be mistaken for teleportation — another commonly reported phenomena associated with the Sedona vortices. A resonance chamber in the hills of Sedona, either naturally occurring or constructed by one of the civilizations that had inhabited the area over the preceding nine thousand years, was a perfectly plausible explanation.

It did not of course explain how Jade was able to “see” an elaborate Vault from the other side of the world, but, Professor thought, one impossible thing at a time.

It took a little over seven hours to make the drive from Edwards AFB to Sedona and then a little further south to the place Jade revealed to be the actual location of the vault, a 547-foot high red limestone butte shaped like a bell — thus the name, Bell Rock — though to Professor, it looked more like a medieval castle perched atop a huge domed mountain.

According to the tourist pamphlets Jade had collected, Bell Rock was one of the four prominent vortex sites in the Sedona area, and rumor had it the mountain concealed an enormous crystal that produced harmonic energy waves — more New Age-y nonsense, as far as Professor was concerned — or possibly a hidden alien city, which now didn’t seem quite as preposterous as it once had. Bell Rock had achieved near-global notoriety in 2012 when a Sedona retiree, obsessed with the belief that all of human existence was actually an elaborate computer simulation — probably after reading one of Roche’s books — claimed that a portal to another dimension would open up during the winter solstice, which not-coincidentally corresponded to the arrival of the overhyped end of the Mayan calendar, and that by taking a literal leap of faith from the promontory, he would be hurled through space and time to the center of the galaxy. Professor could not recall hearing the man’s eventual fate, but he could not ignore the similarities to what Jade had described. Perhaps there was some kind of doorway at Bell Rock, and a resonance chamber that could, figuratively at least, send a person on a cosmic journey.

Was that a secret worth killing for? Evidently both the Changelings and Atash Shah thought so, though for very different reasons. Shah’s faith-based concerns he could understand, even if they were wholly irrational, but what did the Changelings hope to gain from protecting what was essentially a great big hallucination machine?

Jade pulled the car off in a parking area at the trailhead near the highway. It was late afternoon but there were still several other cars in the lot, most of them bearing Arizona license plates, though there were a few from other states. All of the cars had an innocuous well-traveled look about them, but that was exactly the sort of attention to detail he would expect from the Changelings.

Jade got out and went to the trunk. Inside was a small backpack along with an ample supply of bottled water. “Load up,” she said. “The entrance is in a cave about fifty feet up the cliff. We’ll have to do some climbing.”

“That’s a pretty precise estimate,” Professor remarked. “I wonder if you were seeing it as it is now, or as it was when the Hypogeum was first built. Did the vision account for erosion and weathering?”

“Don’t be such a spoilsport. I know exactly where to go. When we get there, you’ll either see that I’m right, or get to crow about me being delusional.”

“I didn’t say you were… You know what, you’re right. Let’s go.”

Jade stuffed several bottles into the pack and then handed one each to Professor and Shah. “It’s not far, but we should probably get moving if we want to get there before dark.”

“Lead the way.” He fixed Shah with a pointed stare. “I’ll bring up the rear.”

A frown flickered across Shah’s face but he did not reply. Instead, he fell into step behind Jade and did not look back. Professor allowed them to get a lead of about fifty yards before heading out. He walked with his hands on his hips, his right hand just a few inches from the Beretta nine-millimeter pistol tucked into his belt at the small of his back and covered by the tail of his shirt. Sievers had brought him the weapon in Australia, and though he only had one spare fifteen-round magazine, he was not as worried about being outgunned by the Changelings as he was being outfoxed by them. A frontal assault wasn’t their style, but that did not make them any less formidable.

The well-maintained trail headed north toward the towering formation, paralleling the highway for the first mile or so. They passed several day hikers and mountain bikers returning to the trailhead, presumably after completing the nearly four mile long loop that encompassed both Bell Rock and the considerably more massive but not quite as photogenic Courthouse Butte to the east. None of the tourists gave them more than a second glance, but Professor varied his stride, sometimes falling back as much as a hundred yards to see if anyone was paying closer than usual attention to them.

When they reached the Y-junction and the beginning of the loop, Jade paused as if taking a rest break. When she sure there was nobody in their line of sight, she left the trail behind and headed due north toward the base of the rock. Professor lingered a few minutes to make sure they were not being observed, and then headed out at a jog.

Jade moved toward the butte as if guided by a homing beacon. Despite his skepticism concerning her supposed out-of-body experience, he marveled at the certainty with which she sped toward her goal, but that was easily enough explained by the fact that this was probably not her first visit to Bell Rock. The Sedona area had been inhabited for thousands of years, and there were ongoing archaeological excavations all over the region. He knew for a fact that Jade had done extensive field work in the Southwest as part of her search for the legendary Seven Cities of Cibola. In the great Venn diagram of life, that had been the moment where Jade’s circle and his had first intersected; Jade had been working with Professor’s former SEAL commander, Dane Maddock.

Even so, a prior visit did not fully account for her laser-like focus. Jade was moving with a purpose, scrambling onto the slope as if following a GPS device in her head, forcing him, reluctantly, to revise his hypothesis. Dreams — and that was the most rational explanation for the out-of-body-experience phenomenon — were rarely a perfect representation of reality. The brain had a way of mixing things up, combining memories and filling in the gaps with subconscious expectations. If Jade’s vision were nothing more than a mental rerun of a previous visit, then he would have expected her to begin exhibiting confusion, searching the terrain for familiar markers to reorient herself. She was most certainly not doing that.

“Up there,” she said, pointing to a weathered draw that ran up to the foot of the sheer vertical slope.

The draw, which channeled rainwater away in the path of least resistance, had been millions of years in the making, just like everything else in the landscape. Caves, like the one Jade had described, were like the bubbles in a block of Swiss cheese, disappearing as the passage of time scoured away the surrounding rock. It would be nothing short of miraculous if the cave Jade sought was actually the opening to an ancient Vault—

“There,” Jade said, pointing up to a shadowy divot about fifty feet above the top of the draw. “That’s the one.”

She opened her backpack and took out a bundle of kernmantle climbing rope, along with three nylon safety harnesses. “I’ll lead and set protection,” she said, as she donned the harness. “We’ll top rope Atash since he’s the least experienced climber here.”

“And you’re the second least,” Professor said. “I’ll lead and top rope both of you.”

She shook her head. “I know the route. It’s a piece of cake.”

“Let me guess. You saw that, too?”

“I saw what I saw,” she retorted. “And I’ve been right so far. Why is it so hard for you to just trust me?”

He decided not to answer that, but gamely slipped his legs into the hoops of the harness and then helped Shah do the same. Jade did not wait for them to finish, but threaded the belay rope through the carabiner attached to the front of her harness and started up the wall.

She climbed quickly, as sure-footed as a spider, setting her first piece of protection — a spring-loaded cam that she slipped into a two-inch wide vertical crack — about twenty feet up. Limestone, formed from the calcium carbonate shells of ancient sea creatures, was sort of like nature’s concrete, but even the hardest rock could crumble under stress. If Jade fell, the camming device was just as likely to be yanked out of the wall as it was to arrest her fall. Jade however seemed unconcerned, as if setting the anchors was merely a formality. Beyond that point, she was less frugal about the gear, putting a piece in place every five feet or so, but she moved with the same purposefulness that had brought her this far. Less than ten minutes after beginning the climb, she pulled herself into the cave opening and set a final anchor.

“I’m up,” she called out.

Professor turned to Shah again. “You think you can do what she just did?”

Shah nodded but without enthusiasm. “If I must.”

Jade’s plan had been for Professor to top rope Shah — maintaining tension of the belaying line so that if Shah slipped, the rope going up to the last anchor Jade had set would keep him from falling. It was the way most beginning climbers got their start, but Professor was having second thoughts about the plan. For one thing, Shah’s safety would depend on whether or not Jade’s anchor held fast. Climbing protection was generally reliable, but if Shah repeatedly lost his grip, the anchor could conceivably come loose.

Of course, the real reason he didn’t like the plan was that it would put Shah and Jade alone together in the cave.

“That’s what I thought. I’m going to go up first. That way, I can pull you up if I have to.” He did not bother giving Shah a crash-course in climbing techniques or how to belay from below, which meant that he would be climbing more or less without anyone to arrest him in the event of a fall, but he trusted his own abilities a lot more than he trusted Shah.

Shah’s hesitancy turned into something more like suspicion, but he nodded again. “Whatever you think best.”

Professor cinched the rope to Shah’s harness with a figure-eight knot. “When I give you the signal, start climbing. I’ll be pulling in the slack from up there, so you won’t be in any danger. Just pay attention to where I put my hands and feet and do the same. Got it?”

Another nod.

“Good.” Professor turned away and, using the anchored rope Jade had set like a thread to guide him through a maze, made the ascent in half the time it had taken her.

“You were right,” he said to her, grinning. “Piece of cake.

The recess was larger than it had looked from below, though it still looked more like a scalloped depression in the limestone than an actual cave. What might once have been the front porch of the mythical Vault now seemed more like a second story exit door with no attending staircase.

Jade shone a flashlight up into the darkest reaches of the niche, revealing a shadowy hole, like the opening to a chimney. It appeared to be just barely large enough to accommodate a person. “That passage leads to the entrance to the vault,” she said, grinning triumphantly. “Believe me now?”

Shah watched from below as Professor disappeared into the shadowy niche. His eyes followed the rope that dangled from the cave entrance, zigzagged through the anchors, and then reached out, like the tentacles of some mythical sea creature to snag hold of the carabiner attached to the front of his climbing harness. His heart was racing but this had nothing at all to do with the impending climb.

This was the moment he’d been waiting for. He hastened forward, standing as close to the wall as he could to remove himself from Professor’s line of sight, and took out his phone. He knew he had only a few seconds, but that was all he needed.

Although Jade had been very secretive about their ultimate location, she had revealed enough for him to set a plan in motion. He had assembled a new team of jihadists, college students from the Arab states and Pakistan, disgruntled immigrants from the Horn of Africa, even a young convert from Beverly Hills — the son of a geologist employed by an oil company, who had learned the Prophet’s wisdom during an extended stay in Yemen. Shah had been able to make all the preparations surreptitiously, sending text messages and posting to the chatrooms whenever an opportunity presented itself. Now, his team was ready. Only one thing was lacking.

He opened the text message app and hit the menu button marked: “Send my current location.”

He returned the phone to his pocket and took a step back from the wall, looking up expectantly, awaiting the signal to begin climbing.

Despite the unpleasantness at the airport, he bore no ill-will toward Jade Ihara or her friend — she called him Professor, but he seemed more like some kind of government agent, maybe a Special Forces soldier assigned to safeguard her. All Shah cared about was preserving the status quo. He genuinely hoped no one would be hurt, not even Jade’s antagonistic companion, but he would do whatever had to be done to make sure that no one ever had cause to question the legitimacy of Islam.

After a few minutes of waiting, he heard Professor call out to him. He waved back and then put his hands on the wall. Up close, it didn’t look so daunting. There were protuberances he could hang onto and cracks he could jam his fingers into. It was not that different than climbing a ladder, albeit a ladder where the rungs were randomly spaced and no bigger than a peanut. Or at least it seemed that way until he could no longer touch the ground with an outstretched foot. Then his heart began pounding again, and this time it had everything to do with the climb. He clutched at the wall, pressing himself flat against it, afraid to move, and almost immediately felt the rock slipping away beneath his fingertips.

A terrified but incoherent cry escaped his lips. Some part of him knew that it wouldn’t be a fatal fall, but it would hurt. He might even break a bone or—

He did not fall. The rope cinched to his harness pulled taut, arresting his downward plunge, and he banged against the wall, though not with enough force to cause injury.

“Find your holds,” Professor advised from above. “Three points of contact. It’s not that hard.”

“I can’t,” Shah gasped. “Let me down.”

“If that’s what you want.”

Shah thought he heard a note of mockery in the other man’s tone. The perceived insult, coupled with the knowledge that, if he did not make this climb, he would never know what lay inside the vault, was enough to help him regain his composure. “No!” he shouted. “No. I can do it.”

“That’s the spirit,” replied Professor. “Loosen up. If you keep hugging the wall like that, you’ll wear yourself out.”

Heeding that advice was easier said than done. A primal fear of falling kept him gripping every hold so tightly that the tendons in his forearms felt like they were about to snap. Nevertheless, the further he went up the wall, the more confident he felt. The earlier mishap had taught him to trust the rope, trust that even if he lost his grip again, he would not fall. When he reached the top, Professor extended a hand to him and pulled him the rest of the way up.

“Congratulations,” he said. “You’re a rock climber now.”

Shah was drenched in perspiration and it took him a moment to catch his breath, but he was smiling so broadly that his jaws hurt. “That was amazing. I wouldn’t mind trying that again sometime.”

“You’ll like rappelling down even more.”

Shah looked past him. “Where’s Jade?”

“Scouting ahead.” He pointed to the impenetrable darkness at the back of the cave.

As if on cue, a faint glow appeared there, growing brighter by the second as the light source moved closer and eventually filled the mouth of the passage that led deeper into the mountain. A moment later, Jade’s face appeared in the opening. She did not look happy.

“I know that look,” Professor said, his tone grim. “What’s wrong?”

“The entrance chamber. It’s completely flooded. And I’ll save you the trouble of asking.” She sagged in defeat. “I didn’t see that.”

TWENTY-FIVE

Shah was incredulous. “Flooded? In Arizona? How is that possible?”

Jade squeezed her eyes shut, recalling the vision from the Hypogeum. She had seen a round chamber at the end of the passage, and the three circles that appeared to be linked but really weren’t. There had not been any water. She related exactly what she had seen to Professor.

“I think…” She hesitated. “Could this be how the timelock mechanism works?”

Professor nodded in understanding. “That makes sense. Water clocks have been around a long time. The Chinese may have created water clocks as far back as six thousand years ago. Water flows at a constant rate. Even though this is the desert, there’s plenty of rainfall in the monsoon season. Rainfall on the top of the rock seeps down and recharges the reservoir. Throw in a sufficiently complex clockwork mechanism, and you could make a water clock that keeps time over very long periods.”

“So we have to wait until it drains?” Shah said. “We just come back in… Ha! We don’t even know how long to wait. Wonderful.”

“We could probably pump the water out,” Professor said, though his tone suggested that he considered this a measure of last resort rather than the best way forward. “I doubt very much we could pull that off without attracting a lot of attention.”

“If the chamber was dry, we’d be able to unlock the vault,” Jade said, thinking aloud. “Those rings are the key. They’re like a… a pass code or the combination to a safe. Maybe we don’t have to actually drain the chamber to open it.”

Professor’s eyebrows drew together. “SCUBA?”

“Why not?”

“Well, for starters, we don’t have any gear. We’d probably have to drive to Phoenix to find a dive shop, which we wouldn’t be able to do until tomorrow. And someone is bound to ask why we’re hauling gas cylinders and wetsuits up the trail. But aside from that, the biggest problem I see is hydraulic pressure. Water is heavy. About eight pounds to the gallon. I don’t know how big this chamber is, but let’s say it’s about the same size as a backyard swimming pool — roughly ten thousand gallons. That’s eighty thousand pounds. Forty tons, pressing against that locked door. I’m not sure you’d even be able to open it, but if you could, the results could be…well, unpredictable to say the least.”

Jade managed a wan smile. “We can handle unpredictable.”

Professor threw her a withering glance.

“How about this,” Jade went on. “I’ll swim into the chamber and try to get a better look at it. Maybe then we’ll have a better idea of how to get it open.”

“You want to free dive in a cave? You want to swim into a dark cave, have a looksee, and then find your way back out, all on one breath? Cave diving is insanely dangerous under the best of circumstances. Without gear? No. It’s suicide.”

“I can hold my breath for two minutes. That passage drops right into the cave, so I could spend a whole minute looking around, and have plenty of time to get back out. We can pull the rope up and I’ll tie off. That way I can’t get lost and if anything goes wrong, you can pull me back.”

Professor started to say something, but Jade cut him off. “I know, you think you’re the stronger swimmer, so you should go. But I’ve seen that chamber in my vision. I know I can figure out how to open it.”

Professor shook his head. “I wasn’t going to say that. What would be the point? Once you get an idea in your head, there’s no reasoning with you. I was going to say that maybe we can make some field expedient swim goggles so you can at least see what you’re doing.”

He took a half-filled water bottle from his back pocket, drained the contents in a long swig, and then held the empty plastic container up. “Should be able to do something with his.”

“Oh. Why didn’t you just say so?”

“Get the rope,” he said. “And give me your knife. I lost mine in Australia. Once more thing that trip cost me.”

Jade passed over her Swiss Army knife and then went to the edge of the cave mouth to gather up the belaying line. She knotted the end to her climbing harness and then threw the rest of the coil onto her shoulder. Professor, meanwhile sliced out two oval shaped pieces from the bottoms of two plastic bottles. He pressed them to his eyes and scrunched up his face to hold them in place.

“They’ll be leaky,” he said, removing them and handing them to her, “but they should be good for thirty seconds or so.”

Jade tried the makeshift lenses. The edges were sharp, digging into her skin, but the discomfort was a small price to pay for being able to see clearly underwater.

Professor wasn’t finished however. He took out the sketch of the circles and began drawing something new beneath them. “Borromean Rings are an impossibility using true circles. An optical illusion like something from Escher. But if you use slightly elliptical circles positioned at angles in three dimensions, the perspective changes make them look like circles when viewed top down. Sort of like this.”

He held up the new sketch.

“Look for something like this. Then you’ll know you’re on the right track.”

“You’re kidding. Those are the same?”

He nodded. “More or less. This is only one possible solution of course. But keep your eyes open for it.”

She squinted through the eye cups. “If I open my eyes too wide, these things will fall out, but I’ll do my best.” She handed him the climbing rope. “I tug on this as soon as I’m in the chamber. After that, if I give two sharp tugs, pull me back.”

“And if you aren’t out in sixty seconds, I’ll drag you out anyway.”

“Make it ninety. I want to be able to take my time in there.”

“Fine, but not a second longer.”

“Wish me luck.” With that, Jade turned and headed back up the narrow passage. It was cramped. Professor would probably be able to scrape through, but barely. During her earlier exploration, she had been forced to crawl backward since there was no room to turn around at the far end; merely an opening about a foot above the water’s surface.

She reached the opening and thrust her flashlight into the submerged chamber. The waterproof light revealed an enormous murky void and not much else. The water was chilly on her skin and immersion in it would be bracing, but not enough to cause hypothermia in the minute and a half she would be in it. She looked over her shoulder, back down the length of the passage but was unable to see Professor or Shah. She took several quick breaths, hyperventilating to oxygenate her blood, and then, with one hand holding the eye cups in place, she plunged forward, headfirst into the water.

The slap of cold was about what she expected and she had to fight the urge to let all her air out in a howl of dismay. Her natural buoyancy immediately tried to bring her back to the surface, and water began infiltrating the makeshift goggles, but in that first moment, she got her first real look at the entrance to the vault.

Being in the chamber was, Jade thought, like swimming in a municipal water tank. It was about twenty feet across and perfectly spherical, save for the strange and seemingly haphazard gaps and protrusions that ruined the otherwise perfect symmetry. As she studied the relief, looking for some kind of recognizable pattern, Jade felt something tugging at her waist.

Crap. I forgot. She found the safety line with the hand that held the flashlight and gave it a single hard pull, hoping that Professor would not misinterpret the signal and drag her out. She had already been in the water for a good fifteen seconds, and something told her she had overestimated her ability to hold her breath in the chilly conditions. When the rope did not go taut again, she assumed the message had been correctly received, and returned her attention to the walls of the chamber.

The momentary distraction gave her a fresh perspective, though the water seeping into the eye cups left her vision blurry. She realized now that, despite differences in depth, the grooves and protrusions still reflected the curvature of the surrounding chamber. It was almost as if large square sections of the wall had been excised to reveal another sphere underneath, and then another beyond that, like the layers of an onion.

A sphere inside a sphere inside a sphere. Almost like Professor’s second drawing.

Inspired, she swam closer to the wall and pressed against one protruding square, about two feet on each side. When that yielded no results, she moved her fingers to the edge and tried pushing it sideways, like sliding a window open.

The stone moved laterally, but as it moved, it caused other sections to move as well.

It’s a puzzle, Jade realized. Like an enormous inside out Rubik’s Cube. Move one piece and the whole puzzle changes. But what’s the solution?

The answer was so obvious, she felt stupid for not realizing it immediately. The key to the puzzle, and the combination that would unlock the door to the vault, was embodied in the riddle of the Borromean Rings.

She swam sideways, trying to take in as much of the inside out orb as she could. Now that she understood what she was supposed to do, she had no difficulty visualizing the finished product.

There were four layers in all. The deepest was a perfect sphere. The squares of varying thickness would have to be moved around to form concentric circular bands that corresponded to the arrangement in the drawing Professor had shown her. None of the square sections was perfectly flat, nor were any two the same, even those that were of the same layer. Some of the edges met perfectly, while others differed by as much as an inch.

The longer she studied it, the more obvious the solution became.

I can do this. But I need time.

The burning in her lungs and the involuntary spasms in her chest told her that she was already out of time. She needed to breathe, needed to be out of the cold water. She followed the safety rope up through the murk to the top of the spherical chamber. There was a small air pocket there, supplied by the opening through which she had entered, and she floated there for a moment, greedily sucking in fresh air. The rope hung down a few feet away, marking the location off the exit. She could just pull herself up, back into the passage, crawl back and tell Professor what she had discovered. They could come back with SCUBA gear, wetsuits and high-powered lanterns…maybe sneak them in after nightfall. The Vault wasn’t going anywhere, after all. What was another twenty-four hours?

I can do this, she thought again. Right now. I can open the vault.

She stared at the opening. I should tell him.

And if he says no?

He probably would, but in their particular working relationship, she was the boss, not him.

“Hey!” She directed her shout up into the opening. “Can you hear me?”

She heard Professor’s voice a moment later, hollow sounding, like someone speaking into a tube. “Jade?”

“I found something. Give me a few more minutes.”

There was a long silence, so she called out again. “Did you hear me? I found something.”

There was something different about the way her voice echoed down the passage, and a few seconds later, she realized why when Professor’s face appeared in the opening above. “What did you find?” he asked.

“I know how to open it,” she said, through chattering teeth.

“Jade, this wasn’t the plan.”

“Trust me. This will only take a minute.”

“That’s what you said a minute ago. Your lips are turning blue. Come out. Now.”

“No, they aren’t.” She dumped the water from the eye cups and jammed them back into place. “Be right back.”

Before he could protest further, she ducked under and went back to work. She darted back and forth inside of the spherical chamber, moving one section left, then another down, then another left.

This time, there was no uncertainty in her actions. She went immediately to the wall and began pushing the square sections this way and that, connecting matching layers to form bands that would encompass the chamber. The stone sections moved easily, with only minimal resistance, hardly what she would have expected from a limestone cave submerged in water, but then this was no mere cave. It was a Vault for the Ages, built to withstand the passage of thousands of years.

The comparison to a Rubik’s Cube was apt, since each time she moved one of the stone sections horizontally or vertically, it would affect everything else on the same plane, but she quickly figured out how to use this to her advantage. Fortunately, this puzzle was a lot simpler than the multicolored-cube. In thirty seconds time, she completed one of the bands, and saw in her mind’s eye the sequence of moves she would have to complete to finish the other two.

Breathe!

She swam back up to the air pocket, breaking through the surface with a splash and a gasp. “Professor?”

She tried to shout it, but her teeth were chattering uncontrollably and she could barely get the word out.

No answer. She searched the top of the air pocket, trying to find the opening or at the very least, the dangling safety line, but found neither.

A cold fist of dread slammed into Jade’s gut. She reached for the rope knotted to her climbing harness and began frantically pulling in the line, even though she knew what she would find. Sure enough, after pulling in twenty feet of sodden rope, she reached the end, which had been severed neatly, as if by a pair of scissors.

“Damn it!”

As she had maneuvered the pieces of the three-dimensional puzzle, reorganizing the stone squares into the ring-like bands, she had inadvertently covered the opening overhead and in so doing, sliced through the safety line. She was cut off from Professor and Shah. Worse, she was trapped inside the sphere, with only one way out.

That wasn’t strictly true. If she moved the stones in the right sequence, she might be able to uncover the opening again and get out, but that would mean trial and error, a time-consuming process, and time was not something she had in abundance — and when it was done, she would have to start the puzzle all again.

No, practically speaking, the only way out was to align the rings, solve the puzzle and open the vault.

She tried to inhale deeply to fill her lungs again, but the cold had left her muscles rigid, and she was only able to take a shallow stuttering breath. It would have to suffice.

She swam back down, attacking the puzzle with frenetic urgency. Shift right. Slide down. Shift right. Slide up.

Breathe!

No. Almost done.

Shift. Slide. Shift.

Breathe.

A spasm racked her chest. She blew air into her cheeks then breathed it in, trying to fool her autonomic nervous system. It didn’t really work, but the attempt dislodge the plastic bottle lens over her left eye, and as it drifted away, a rush of frigid water pressed against her eyeball.

Keep going. Almost done.

Slide, shift, push… And then, she saw that only one more move remained. When she pushed the stone into place, the puzzle would be solved and the pattern of interwoven rings would be formed. What happened after that would be, as Professor had indicated, unpredictable.

In a perfect world, the chamber would drain slowly and a concealed door would open, but Jade doubted her luck would be that good. It was far more likely that the door had been designed to be opened only when the chamber was dry, something that might happen only every thousand years, which mean that either the door would not budge, and she would still be trapped, or the rush of water through the newly opened portal would create a vortex with enough hydraulic pressure to suck her down and conceivably rip her limb from limb or smash her to a pulp against the walls of the vault.

She left the last stone as it was and kicked back up to the air pocket, hoping against hope that she would find Professor staring down at her, irritated but overjoyed to see her, but there was only the smooth wall of the sphere, with two bands of stone, one seemingly passing over the top of the other.

There was only one thing left to do.

She swam down, following the carefully organized bands of stone that now circumscribed the inside of the sphere, until she found the one piece that was still out of place. Without any further hesitation, she swam to it and gave it a final push. She did not wait to see the results, but immediately began kicking her legs for the surface. The sudden maneuver cost her the remaining eye cup, throwing everything into blurry indistinctness, but she kept kicking, racing toward the top of the chamber. Even though she could no longer see the smooth walls of the chamber, she could feel vibrations in the water around her. Something was happening. The interior of the sphere was moving.

She broke the surface with a gasp. The water was rippling all around her, and when she trained her flashlight straight up at the exposed section of the chamber, she saw why. The stone bands representing the Borromean rings were moving, rolling on three axes like a gimbal.

Suddenly, the entire chamber started coming apart. The square sections seemed to drop out of the ceiling, collapsing toward her. She threw up her hands to cover her head, but in that moment, she realized she was no longer floating, but falling. The water around her had disappeared as abruptly as if the entire bottom of the sphere had broken open, creating a whirlpool. Jade barely had time to gasp for air before she was caught in the frothing deluge and flushed away.

TWENTY-SIX

“Jade!” Professor hammered his fist against the smooth stone that had unexpectedly slid over the entrance to the underground chamber, blocking his access to Jade and slicing through the rope that was her only lifeline. His shout was as ineffectual as his pounding. Jade was cut off, beyond his reach.

“Damn it!” he raged, punching the stone again. “I told her this would happen.”

“What’s wrong?” Shah’s voice drifted up the short but cramped passage.

“I don’t know,” Professor replied, and that wasn’t a total lie. “Jade was trying to open the door, but now we can’t get through.”

“What does that mean? Is it some kind of booby trap?”

“I don’t know what it means,” he snapped. Then he took a calming breath. “We’ll just have to wait and see. Jade said she knew how to open it. She’s headstrong, but she’s pretty good with stuff like this.”

“So I’ve noticed.” Shah’s murmured comment was barely audible, and not just because he was speaking from the far end of the passage.

A strange hissing sound, like stone rasping against stone, filled the air, along with a faint but persistent vibration that seemed to be rising up through the rock.

Cave-in?

Professor’s first impulse was to scramble back down the passage, and maybe even take his chances sliding down the sheer limestone face they had climbed, in order to avoid being entombed beneath tons off falling rock, but he fought this urge, and focused his attention instead on identifying the source of the disturbance. A moment later, he realized that the smooth rock blocking the entrance to the submerged chamber was moving. He reached out to it, touching it lightly with a fingertip, and felt it rolling in place like an enormous ball bearing.

What did you do, Jade?

The tremor intensified, but the sensation of movement against his fingertip vanished, along with the stone that had been blocking the passage. Professor could now feel cold musty air rushing up through the opening. The breeze lasted only a moment, like the last exhalation of a dying man, but it was strong enough to tousle his hair. A few seconds later, the vibrations ceased and all was still.

Professor reached his hand a little further into the gap, felt nothing, and then shone his flashlight into the void. Instead of reflecting off the water that had been there only a few minutes before, the beam revealed what looked like stone steps disappearing down into the earth.

“Jade!” His shout echoed back but there was no answer from the depths.

He felt his pulse quicken, his body leaping to the obvious conclusion even before the thought could fully form in his brain. Jade was gone. Swept away.

“No. She’s alive.” He said it aloud, as if doing so might convince the universe to change its mind.

“What’s happening?” asked Shah.

Professor paid him no heed. He lowered himself through the hole and placed his feet on the steps. Once inside, he could see that the steps were formed of stone blocks, each about twenty-four inches to a side, stacked up to form a descending spiral staircase. There was a wall of tightly joined cut stone blocks to his left, and a yawning chasm, sixteen feet across, to his right, around which the steps coiled like the threads of a screw hole. The walls and steps were damp, but that was the only remaining trace of the water that had earlier filled the chamber.

“Jade!” Professor started down the steps, moving faster than was probably advisable given the unfamiliar environment, calling out to Jade over and over again, always with the same results. The stairs circled once, twice. His best rough guess put him thirty feet below the entrance with no end yet in sight, and no sign of Jade. He completed another orbit, screwing deeper into the earth, then another, and then the descent ended at a flat landing that curled once more around the open pit. At the end of the landing was an opening that led through the wall.

Professor stopped in front of the doorway and shone his light through. The landing was damp like everything else, but the stone floor on the other side of the opening appeared to be bone dry. About ten feet past the opening, a smooth stone wall — all the surfaces looked like burnished concrete rather than natural stone — curved away in either direction.

The absence of any footprints in the dry passage beyond told him Jade had not left by that route. He crossed back to the edge of the landing and leaned over, shining his light into the depths.

“Jade!”

Shah came down the steps. “This place is incredible. No one knows about it?”

Professor continued ignoring the other man. Short of taking a leap of faith into the unknown, there seemed no way to reach the depths below, but someone had gone to the trouble of excavating the chasm, and if he was not wrong, lining it with cement, and that strongly indicated a purpose and possibly another means of accessing the lower reaches. He turned back to the doorway and went through, with Shah just a few steps behind. He decided to go left, but ultimately the choice was irrelevant. The wall and the passage beside it curved around, forming a rotunda that probably would have brought him back to the staircase passage, only he never got that far. Halfway around the ring-shape walk, he spotted the glow of artificial light.

“Jade!”

He sprinted toward the light, and as he came around the bend, he saw a woman standing there. It was not Jade, and she was not alone.

The woman was very attractive, with pale skin and raven black hair, and an almost palpable air of haughtiness. Curiously, despite the fact that the light from the portable electric lamp on the floor behind her could hardly be considered brilliant, she wore dark wraparound sunglasses.

Professor only gave her a passing glance. His attention was on the two men standing to either side of her. He recognized both of them. One was Jordan Kellogg, the man who had introduced himself as the assistant editor of Chameleon International publishing house.

The other man’s face was as familiar to Professor as his own. In fact, it was his own. He wore Professor’s clothes, even had his Omega Seamaster wristwatch and his Explorer fedora.

The two men — the two Changelings — had pistols leveled at him.

“I assume you are armed,” Kellogg said. “Let me assure you, it makes no difference to us whether you live or die, but if it matters to you, I suggest you place your weapon on the ground. Slowly.”

Professor raised his hands. Two-to-one odds were manageable, and he wasn’t afraid to get a little scuffed up, but there was a far more compelling reason for him to stand down. “Do you have Jade? Is she all right?”

Kellogg glanced at Professor’s doppleganger. “I told you she’d figure out how to get in.”

“Fat lot of good it did her,” the other man replied in Professor’s voice. “She got washed down into the waterworks. We’ll probably never find her body.”

While Professor did not grasp the context of the exchange, the implication was easily enough understood. The Changelings did not have Jade.

Which meant there was no reason to continue the conversation.

“What about Jade?” he said again. “Do you know where she is?”

He asked the question only to distract the two men. It was physically impossible to pull a trigger while talking, which meant that as soon as one of the men started to answer, he would draw his own weapon and start firing.

Before either Changeling could speak however, Shah stepped forward. “Gabrielle?”

The woman cocked her head in the direction of his voice. “Atash. I’m pleased that you’re here. I had hoped that you would find your way, though we had expected you to pursue Jade Ihara, not join her. I’m very impressed.”

Shah ignored the praise. “So it’s true. You have been working for…them…all along.”

“I am not working for anyone,” she replied calmly. “They are my family.”

“You used me!” Shah fairly screamed the accusation, stomping forward, heedless of the weapons pointed at him.

Professor caught Shah’s biceps to stop his advance. “Get a grip,” he said, speaking almost as loud as Shah had. “They’ve got guns. You’ll just get yourself killed.”

The woman’s head tilted back and forth, bird-like, confirming what Professor had suspected from the moment he saw her sunglasses. She was blind. That fact seemed a lot less important than the matter of her prior relationship with Shah. He addressed the woman. “Gabrielle is it? What am I saying? That name is probably as fake as everything else about you. I take it you’re the partner he’s been talking about. The one who convinced him to go after Jade?”

The woman inclined her head in what might have been a nod.

“That was a real boneheaded thing to do,” Professor went on. “Especially if you already had somebody on the inside.”

“You’re a military man,” Kellogg said. “You know how lines of communication can sometimes get crossed.”

“You could have gotten yourself killed Kellogg or whatever your real name is.” He took a deep breath, surreptitiously lowering his hands an inch or two. “Let me see if I’ve got this straight. You three — and all the rest of the Changelings back at the nest — have known about this place…”

He gestured expansively. “This Vault, all along. You’re the self-appointed protectors, making sure that nobody else finds it, right? If someone gets too close, you kill them. Or…” He nodded to Shah. “Trick someone else into doing the dirty work for you. Roche got too close to the truth, so you had to off him. And hey, while you’re at it, set the Muslims up to be the bad guys. Hell, push the right buttons and they’ll line up to deal some jihad on the infidels who insult the Prophet.”

He sensed a subtle shift in Shah’s ire — away from the blind woman and toward him — which given the circumstances wasn’t such a bad thing. If Shah didn’t take it down a notch, he might get them both killed.

“So what it is, exactly? What’s the big deal about this Vault? What’s so important that you murder people and disappear a whole plane full of people?”

The woman — Gabrielle — smiled. “It’s not for you.”

The words sent a chill through him. “Eve said that. What do you mean? What’s not for me?”

Her statement must have been a signal to Kellogg and Professor’s doppelganger. They started forward, pistols raised and gripped in both hands, bodies and arms positioned in a modified isosceles stance that Professor recognized immediately as the tactical shooting position he had learned in the Teams. For the first time since encountering the Changelings, it occurred to Professor that he might have misjudged their ability level. These men had been trained by experts. He could see it in every move they made.

Professor’s duplicate stopped a mere ten feet away, nearly point blank range. Kellogg continued forward, careful to stay out of arm’s reach, and circled alongside Professor. “Your weapon,” he said. “Where is it?”

It was plain that any show of resistance would be suicidal. Professor raised his hands a little higher. “Under my shirttail.”

Kellogg moved out of Professor’s line of sight and then came in close enough to pluck the weapon from its holster. “Is that the only one?”

“Unfortunately,” Professor replied. He felt a tap against his right ankle, then the left; Kellogg verifying that he did not have a backup weapon concealed there.

“Kneel,” Kellogg said. “Hands laced behind your head.”

Professor remained standing. “If you’re going to kill me, just get it over with.”

“I said—”

The woman cut him off. “It’s all right. Let him stand.” She tilted her head toward Professor. “Contrary to what you might thing, we do not shed blood with reckless abandon. And you may yet have some usefulness to us.”

“This should be good.”

She turned to Shah again. “Atash, are you armed?”

“No,” Shah said, and then echoed Professor. “Unfortunately.”

She reached out to him with an open hand. “Join me. I want to show you something.”

Shah glanced uncertainly at Professor. “Show me what?”

“What you came here to see. The Vault. You do want to see it, don’t you?”

“I…” He swallowed. “I don’t know. What’s in it?”

“Only the truth, Atash. Does that frighten you?” She smiled, which did not soften her arrogance in the slightest. “Gerald Roche was wrong. There was no conspiracy to alter the calendar. No fabrication of history to conceal this supposed ‘Phantom Time.’ That’s the truth you want to hear, isn’t it? You need not fear otherwise.”

“The Prophet?”

“Peace be upon him,” she said, sardonically. “Come with me and I will show you the truth about your Prophet.”

“I don’t understand. Is this another one of your tricks?”

“No tricks, Atash.” She stretched her hand toward him again. “This is for you.”

TWENTY-SEVEN

Somehow, Jade managed to hold on to her flashlight, though it offered little in the way of illumination as she was swept along in the torrent. Caught in the whirlpool, she was spun around so violently that, despite the light in her hands, all she could see for several long seconds was complete unrelenting dark. Her lungs burned and her chest convulsed with the need to breathe, but she could feel water moving against her face and had no way of knowing if she was submerged or not. She squeezed her fist tight around the flashlight, and fought the compulsion to draw in a liquid inhalation until she couldn’t fight it anymore. Her mouth came open in a gasp that drew in neither water nor air but an aerosolized combination of the two. She gagged and coughed, all the while spinning around and around like a sock in the wash cycle.

Something struck her in the abdomen, turning her head over heels, and a blast of water swept across her, filling her mouth and nose once more. Then, the flood passed and she was able to breathe again.

It took a moment for her to realize that she was hanging in mid-air, suspended by the rope attached to her climbing harness. The blow she had felt was the line snagging on something, going taut and dragging her to an abrupt stop as the water rushed away. Even though she was caught fast, unmoving, she could still feel the vortex whirling around her.

When the sensation finally passed, she found the rope and pulled herself upright. The flashlight revealed the smooth wet walls of a cylindrical shaft about twenty feet in diameter. She was off center, dangling about five feet away from the wall. Though she could not make out the bottom of the well, she could see a ledge ringing the shaft about twenty feet above. The ledge was not a solid piece of stone, but composed of individual blocks jammed together tightly. Her trailing safety line was caught between two of the blocks like a string of floss between two molars. The improbability of this apparent reprieve did not escape Jade’s notice, but she had more immediate concerns than wondering why fate had chosen to intercede on her behalf.

She stared at the rope for a few seconds, searching her memories of climbing lessons past for the best technique to make her way back up the rope. The nylon sheathed line was not thick enough to grip effectively. There were two perfectly good mechanical ascenders in her backpack, along with the rest of the climbing gear, but she had left the pack behind when she had gone into the water. She thought she might be able to use the carabiner on the front of her harness as a field-expedient ascender, but to do so would require unclipping the safety line, which would send her to the bottom in a hurry. The next best thing to a mechanical ascender was a Prusik, a friction hitch knot that could be fashioned out of a shoelace or a piece of paracord. When tied around a belay line and fashioned into handhold loops, a climber could slide the Prusik up a few inches at a time, and eventually regain her position after a fall. Jade stared at her boots, wondering how much effort it would take to remove the laces, and if there was a better option.

“Yo-yo,” she murmured, and that was what she felt like; a child’s yo-yo toy that had reached the end of the string and lost all its momentum.

Maybe she could rewind.

She reached up again, gripping the rope as hard as she could, and pulled. She managed to raise herself several inches, easing the tension on the rope a little, but knew that if she let go with either hand, she would immediately lose whatever progress she had made, unless she found a way to gather up the slack. When she was certain that she couldn’t lift herself any higher and felt her arms starting to burn with the exertion, she whipped her upper body around the rope, coiling up the slack around her waist.

Her grip failed and the rope went taut again, constricting her mid-section, but she had gained almost twelve vertical inches.

“Okay. Just need to do that nineteen more times.”

She reached up and pulled—

The rope slipped from between the stone blocks with a loud twang and then she was falling.

The first full second or two of the fall was weirdly distorted by the panic-induced rush of adrenaline that amped Jade’s brain into hyper-drive. A single thought ricocheted around her brain: how far to the bottom?

But after three seconds of falling—How far is that? How fast am I falling now? — the question of distance became less important than the question of what she would encounter when she reached the end of the vertical journey. If it was solid rock, then she would either die on impact or wish she had. But if it was water….

If it was water, deep enough and not too much further down, she might survive.

She brought her hands together in front of her lower torso, the flashlight still squeezed in her fist. She kept her legs straight, toes pointed down and feet pressed together tightly. The flashlight illumed the darkness around her, but she was moving faster than her brain could process, so she simply closed her eyes and—

The impact shuddered up her feet all the way to her hips, but the chilly water was considerably more forgiving than solid limestone would have been. She arrowed deep, so deep that the pressure against her inner ear became uncomfortably intense — one more painful sensation reminding her that she was still alive. Too late to make a difference, she threw her arms and legs wide to slow her descent and immediately started kicking furiously back toward the surface. The pressure in her head relented slowly, but the spasms in her chest intensified as the surface remained maddeningly out of reach.

She felt like she was clawing her way out of Hell.

When she finally broke the surface, she was too spent to do anything more than lie on her back, floating motionless, trying not to think about the pain crackling along her shin bones.

The break did not last long. Professor was still up there, probably thinking the worst. And if she didn’t find a way out of the pit, surviving the fall would mean a protracted death of hypothermia. She played the light in every direction, but saw only the same smooth walls she had seen from above. The rocks that had briefly snagged her rope were too distant to make out.

Damn.

But the walls of the shaft were too smooth, too perfectly round to be the work of nature. In some ways, the handiwork reminded her of ancient Roman structures, which despite the passage of thousands of years remained mostly intact. Some ancient craftsman had labored in the spot where she now trod water. Someone had carved out a cistern in the limestone to reclaim the water from the submerged chamber above, and that gave her hope. If the shaft had been cut for some purpose, then logically, there had to be a way to access it. If not above the water’s surface, then perhaps below.

While the idea of another free dive did not exactly thrill her, the possibility…no, the certainty that she would find a way out compelled her. She filled her lungs and then plunged beneath the surface, diving in a corkscrew pattern around the perimeter of the well, shining the flashlight beam on the walls looking for an intersecting tunnel.

There it was, a dark opening about six feet across.

What if it goes nowhere at all? What if it feeds into a maze of pipes and I can’t find my way back to the surface?

It was a choice between a slow death on the surface or a quick end from drowning. Neither fate was more appealing than the other, but not exploring the submerged passage was certain death.

She swam into the pipe, kicking and clawing her way forward. After more than half a minute of hard swimming, she spied the telltale flat shimmer of air above the water’s surface, and kicked urgently toward it.

She came up in a large pool, surrounded by a gymnasium-sized chamber with cylindrical pillars rising up from the water to support the high ceiling overhead. She dog-paddled for a few seconds, playing the light in every direction, until she spotted a flat stone walkway that rose just a few inches above the water. She paddled over and hauled herself up onto it.

Solid ground had never felt quite so good.

But she was a long way from safe. When she was sure that her legs would support her weight, she gathered up the rope that was still attached to her climbing harness, coiling it and throwing it over one shoulder, then headed toward an arched passage that led away from the pool. She was about halfway to this intermediate goal when the ghosts began to appear.

The flash of movement in her peripheral vision startled her, as it always did, but once she realized what it was, she tried to ignore the infrasound induced hallucinations. This strategy worked for the length of time it took for her to reach the mouth of the passage. That was when the ghosts started talking to her.

She jumped in alarm, whirling around to face them, positive that this time, there would be a real person there…but the ephemeral phantoms had already retreated to a different threshold of perception.

The voices, like the ghost figures, gave the impression of being real, but lacked the necessary substance. It was not merely that the speech was incomprehensible. The words were not words at all, but tortured unnatural sounds, like someone playing a recording backwards. But then, from the midst of the aural chaos, a single word rang out.

“Jade!”

“Professor! I’m here!”

The stone consumed her shout, absorbing it completely, returning no echo.

The weird cacophony resumed.

“Screw it. There’s got to be a way out of here.” She started forward again, ignoring the figures flitting about in her peripheral vision, paying no heed to the noises that she knew were probably inside her head.

The passage led to a spiral staircase which she mounted without hesitation, charging up two steps at a time, pain and exhaustion as ephemeral now as the hallucinated phantoms.

More real words found their way into the mishmash of sound, as if moving up the staircase was akin to tweaking the tuner on an old analog radio. Garbled static one moment, the next, someone talking plain as day.

“They are my family.” A woman’s voice, but Jade did not recognize it.

“You used me!”

That was Shah. This realization was followed by another far more disconcerting one. There’s someone else in here.

These voices were not auditory hallucinations. She was certain of that. They were real, filtering down through the levels of this strange citadel hidden under the mountain. That meant Shah and Professor had found their way in, but someone had come in after them.

Changelings.

What about Professor? Is he safe? She almost called out again, but realized that if she could hear them clearly, they might be able to hear her as well, and that would ruin any chance of taking them by surprise.

She kept going, consciously trying to lighten her step as she bounded up the stairs. The voices blurred back into random discharges of noise, though once or twice she thought she caught a recognizable word or a hint of the woman’s voice.

The sight that greeted her at the top of the stairs was no hallucination, but that did not make it any more believable.

She had expected another chamber, or perhaps a cramped tunnel snaking through solid rock like wormholes in a sponge. Instead, she found herself surrounded by empty space… or very nearly empty.

She knew there must be cavern walls and a ceiling of stone high overhead, but these limits were beyond the reach of her light. The staircase she had just ascended appeared to rise up the middle of a cylindrical tower, and she now stood at its summit. There were several other towers of varying heights — one of them was probably the shaft she had fallen through after solving the puzzle at the entrance — all connected by stone bridges, but the network of towers was possibly the least amazing thing her eyes beheld.

Aqueducts curled around the towers, supplying water that turned stone wheels and gears, which in turn drove enormous vertical shafts and screw pumps that conveyed water up into the dark reaches overhead. Other structures, which resembled enclosed walkways or perhaps air ducts on a massive scale, wove through the midst of the waterworks, curling around the towers. The curves were reminiscent of a musical instrument. The water and air flowing around the cylindrical towers were creating a veritable storm of resonance frequencies combining in intricate but inaudible infrasound patterns to dizzying effect. In a leap of intuition, Jade realized that the Vault was not some hidden fortress or citadel where the knowledge of the ancients had been secreted away.

It was a machine.

More precisely, it was a sophisticated computer that employed mechanical logic systems, and utilized an infrasound interface.

This realization unlocked a memory, implanted during her experience in the Hypogeum, but incomprehensible without context. She had been here before, though only in a disembodied state. The recollections were not perfect and they did not come all at once, but she grasped, albeit in a very basic way, how the pumps and ducts, and the acoustic design of the towers and indeed the entire underground chamber, functioned. More importantly, she knew where she needed to go next.

She sprinted onto the bridge that led away from the tower and crossed to another. The visual and auditory phenomena chased after her, but it was just so much background noise now. From time to time, she caught a word — Shah or the woman she’d heard before — but never enough to make sense of what she was hearing.

The bridge connected to a larger cylindrical tower that stretched from the cavern floor below to the unseeable reaches above. It might have been a massive support column, but Jade knew it served a far more important purpose. If the vault was a computer, then this was its central processing unit.

An arched opening led inside the cylinder, where she found herself immediately confronted by a choice. To the left, a flight of stairs curled upward, following the curve of the wall. To the right, the stairs went down.

Up felt like the correct decision, so she headed in that direction and bounded up the stairs. She ascended for at least a full minute, the stairs stretching up in the cramped confines of the passage like something from a surreal nightmare. Thankfully, the ghosts and whispers had not chased after her. Something about the composition of the stairwell walls evidently shielded her from the infrasound effects. When she caught a glimpse of a lurking figure, she knew the seemingly endless ascent was nearly at an end. She was not wrong.

The stairs brought her to a wide balcony overlooking a bowl-shaped pit that occupied the center of the cylindrical column. The pit was not deep, in fact it looked to be only about twenty feet from the top of the utilitarian stone guardrail to the bottom. The balcony ringed the pit, and on the opposite side, the stairs continued, disappearing into the space between the outer and inner walls. Overhead, the pit was mirrored by a domed ceiling which, Jade now realized, created yet another spherical chamber.

“If you’re going to kill me, just get it over with.”

The voice startled her, and not just because of its clarity.

Professor?

It was definitely Professor, and what he had just said confirmed her worst fears. He was in trouble. Either Shah had betrayed them and somehow gotten word to his jihadist confederates, or the Changelings had caught up to them.

That question was answered a moment later when she heard Kellogg’s voice, and then the woman she had heard earlier. The voices seemed to be coming from the pit, but Jade knew this was just an acoustical trick. They were close, probably in a room or passage somewhere above this place.

She ignored the not-too-distant conversation and turned toward the rising stairs. She did not know what she would do when she found the others. Judging by Professor’s statement, the Changelings were armed and she was not. Maybe she could distract them and give Professor a chance to gain the upper hand. She would think of something once—

She stopped suddenly as if a wall had suddenly appeared in her path. In a way, that was exactly what had happened, although the wall was not a tangible thing of limestone or concrete. Rather, it was a sensation, like a kind of magnetic repulsion pushing her back. She felt an overwhelming premonition, not of danger exactly, though that was certainly part of it, but of having missed something profoundly important.

She turned back, and it was as if the magnetic poles reversed. She staggered toward the balcony rail, throwing her arms around it for fear of being pulled over. The attraction was all in her head and she knew it, but that did not make the sensation any less real.

I need to go down there, she thought. The answers are down there.

Some part of her offered a weak protest. Professor needed her. Urgently. Whatever this was, it could wait.

But she knew it could not wait. A window of opportunity had opened. The Vault was offering her its secrets. If she turned away now, the window might close forever.

She had to know.

Jade shrugged the rope coil off her shoulder, wrapped the loose end around the rail, securing it with a bowline knot, and heaved the rest over the side. With a couple of quick adjustments, she reconfigured the carabiner on her climbing harness into a rudimentary rappelling brake and then eased herself over the railing.

She reached the end of the rope and hung there in darkness, just a few feet above the floor. Her flashlight revealed a chamber that was remarkably like the Oracle Room in the Hypogeum, but with one significant difference. Scattered across the floor of the pit were dozens of smooth shapes that, from above, had looked like scattered stones. Now she saw that they were elongated skulls.

She dangled above the grisly tableau, turning slowly, playing her light in every direction, looking to see what other mysteries the pit concealed.

“Okay, you got me here. What am I supposed to—”

Before she could complete the question, the vortex opened and she was swept away again.

TWENTY-EIGHT

Professor had no idea why he was still alive, but he sensed his execution had merely been postponed.

Kellogg and the other Changeling — the man who still wore his face — walked a few steps behind him, their guns still trained on him, though not quite as aggressively as before. They kept a safe stand-off distance, close enough to maintain control but far enough away that Professor would never be able to get the jump on them. Further evidence of professional training. Shah and the woman walked ahead of them, continuing along the rotunda. Her hand was on his arm. It might have been a merely practical arrangement, a blind person and her guide, but Professor doubted the woman needed any assistance finding her way and there was something possessive in her manner. Shah seemed to be tolerating her touch, but only just.

“What is this place?” Shah asked. “Who made it?”

“Better that you see the answer for yourself,” the woman replied. “Know this, however. It is old beyond imagining. A gift of knowledge sent from the heavens.”

“Knowledge?”

“A revelation.” The woman made an expansive gesture. “The prophets of old came to this place in secret to receive the Word. Now the gift of the revelation is given to you.”

“The Prophet came here?” Shah shook his head. “No. The writings are clear on this. Muhammad was visited by the angel in a cave near Medina.”

“Do you believe he could not have traveled, in secret, across the sea to this place? The cave where your Prophet prayed was a resonator, an echo of this place, just like the Hypogeum. He saw the way to the vault, just as Jade Ihara did. The revelation is not for everyone. It wasn’t for her, but it was for him, just as it was for the prophets of old who came before. Jesus. Moses, Abraham. Adam. And now, it is for you.”

Shah was incredulous. “They all came here?”

“All. A vision is given and a prophet goes forth. But with the passage of centuries, confusion sets in, the people lose their way, and it is necessary for another prophet to be called.”

“And I’m supposed to be the new prophet?” Professor thought Shah sounded skeptical rather than awed. “The chosen one.”

“You were meant for great things, Atash.”

“Chosen by you,” Shah said, insistently.

The woman stopped and turned her face toward Shah. “Who do you think we are, Atash? We have been safeguarding this secret, and watching over all of humankind, for ten thousand years. In the holy writings, we are called angels. Messengers of God.”

“Angels with rubber faces,” Professor muttered. “And contact lenses.”

The woman’s face turned toward him, but she ignored the remark. “Yes, we chose you. That is why I came to you, worked with you to lay the foundation. Roche’s interference forced us to accelerate the timetable, but this was always your destiny.”

“Don’t believe it,” Professor said. “It’s a con. That’s all they are. Con artists, selling whatever lie they think will get you to do what they want.”

He had braced himself against an expected blow from behind, but none came. Instead, the blind woman continued to regard Shah with an intensity that might have been mistaken for worship. “When you have seen, you will be able to decide for yourself whether I am lying or not.”

She pointed in the direction they had been traveling. “Up there, you will find a door. Go through. What you see is between you and God.”

Shah hesitated. “You’re saying the revelations of the Prophet, and all the prophets who came before…came from there?”

An impatient frown cracked Gabrielle’s façade. “What difference does it make? Would you prefer a burning bush? An angel floating above you? You will see what you need to see. Trust me.”

“Spoken like a true con artist,” Professor said.

“Go, Atash. See for yourself.”

Shah stared at her a moment longer, as if there was more he felt he needed to say, but then he turned away and headed off on his own. Professor waited until he disappeared around the curve of the rotunda before addressing his captors.

“Now that he’s gone, would you care to tell me what’s really going on?” He turned around to see if either of the men would give answer, but they were as stonily silent as the blind woman. “No? Then maybe we can talk about why I’m still alive.”

“It’s up to him to decide your fate,” the woman said, not looking at him.

“Him? You mean Shah?” This was unexpected. He had made no secret of his antipathy toward the Iranian journalist, but they had reached an accord and Professor did not think the man would countenance further bloodshed, especially at the urging of the Changelings. Maybe they believed that sparing Professor’s life would give them leverage over Shah, or perhaps they intended to continue using him as a hostage to assure Shah’s further cooperation, but if either was the case, they had misjudged the nature of his relationship with Shah.

“When he has received the vision, he will face a choice. Spare your life and risk you telling the world about the vault, or kill you in order to preserve the secret.”

“Ah, I see. So really, you just want him to be the one to do the dirty deed. Just like when you sicced him on Jade.”

Her smile confirmed his accusation. “You’ve misjudged him,” Professor said. “He hates you. Hates how you used and manipulated him.”

“He will be a different man once he has received the vision,” Gabrielle said, her tone a mockery of reverence. “He will understand that everything we have done was necessary.”

“See that’s what I really wanted to talk about. Maybe you’ve convinced Shah with that nonsense about being angels, but you’ll have to try a lot harder to convince me.”

“And why would I waste my breath talking to a man who is already dead?”

Professor glanced at the two men but their expressions were as inscrutable as hers.

He had worked all the angles, counted the number of steps separating him from the gunman, rehearsed the moves in his head. In some of the scenarios, he succeeded in killing one of the men, but never both. No matter which of them he attacked first, the other would be able to shoot him dead. There was only one scenario where he did not die. Not right away at least.

“Okay,” he said. “No more wasting our breath then.”

He sprang forward, diving at Gabrielle like a baseball player trying to steal second. He could sense the men behind him tensing in response to the attack, fingers on the triggers of their pistols. He didn’t think they would fire. Not if they were trained as well as he thought they were. Too much chance of a stray round hitting the woman. If he was wrong….

But he wasn’t wrong. The two gunmen held their fire and Professor hit the unsuspecting woman and bowled her over. As they went down, he wrestled her body around, using her as a human shield. To keep them at bay, he wrapped one arm around her neck. “I’ll kill her.”

The threat stopped the two gunmen, but Professor knew the standoff would not last indefinitely. In fact, it would probably not last more than a few seconds. If he made good on his threat, he would be throwing away the only thing keeping him alive, ergo he dared not kill the woman. If the two Changeling gunmen had not figured that out already, they soon would. His only play was to double down.

“Drop the guns or I’ll break her neck,” he snarled. He shook her, hard. “Do it! Now!”

When the men did not comply immediately, Professor knew they had called his bluff. Damn it. Can’t kill her, can’t let her go. What did that leave?

He hauled her erect, lifted her off the ground so that his body was almost completely covered by hers, and started walking backward, in the direction Shah had gone. He had no idea whether he could count on Shah for assistance, but standing still was not an option. Unfortunately, his steady retreat was not much different than remaining where he was. The two gunmen matched him step for step, and he could see them growing bolder with each passing second. One of them would charge, or perhaps both at nearly the same instant, and then the loaded dice would be cast.

“Stop!”

The shout from behind startled Professor so much that he almost stumbled. The two gunmen were equally surprised, and whatever offensive action they had been contemplating was stillborn. The shout had come from Shah.

Professor twisted half-around, careful to keep Gabrielle between himself and the gunmen, and regarded Shah warily. Even a quick glance was enough to confirm that Shah seemed changed by whatever he had experienced in the vault. Though he had been gone for only a couple minutes, he appeared shaken, as if the foundations of his entire life had been hit by a magnitude eight earthquake.

“Atash?” Gabrielle’s voice was barely audible. The pressure of Professor’s arm across her throat made it difficult for her to breathe, much less speak.

“I’m here.” His voice was flat, distant.

Shell-shocked, thought Professor.

He stared at Gabrielle for a moment, then met Professor’s gaze. “Let her go.” It was neither command nor plea, but more an indifferent suggestion.

Professor relaxed his hold enough to let the woman gasp in a hoarse breath, but did not release her. “Not until those guns are on the ground.”

Shah turned to the men. “Do it.”

The two Changelings exchanged a look with each other and with Gabrielle, and then by mutual accord, stooped over and placed their pistols on the cavern floor.

“And the one you took off me,” Professor added.

Kellogg produced the Beretta and laid it beside the others.

“Now, take a great big step back.”

The men conferred silently a second time, then complied.

“Shah, how about you collect those guns.”

Shah knelt and picked up one of the pistols, then used his foot to send first one then the other skittering away down the passage he had earlier disappeared into. Professor frowned as he watched the guns vanish into the shadows, wondering if Shah was not thinking clearly or if he had intentionally deprived him of a weapon.

“Let her go,” Shah said again without looking at Professor. “I need to speak with her.”

Professor let his arm drop, allowing Gabrielle to stumble away. As she did, he tried to move nonchalantly in the direction of the cast-off pistols, but Shah immediately stopped him with a meaningful gesture from his gun hand.

“Damn,” Professor muttered, looking up from the gun pointed at him to meet Shah’s eyes. “Well, I can’t say I didn’t see that coming, but I was hopeful. So, I guess the con worked. You’re buying into the Messianic malarkey?”

Shah ignored the jibe. “Gabrielle, what I saw… Tell me it’s a trick. Special effects or something.”

The blind woman shook her head. “No tricks.”

Shah was not satisfied with the answer. “Jade Ihara said that sound frequencies can trigger hallucinations. Is that what happened?”

“Would you question the means by which God chooses to deliver his message? If he called you on your phone or spoke to you from a television set, would you consider that unseemly? The message is what it is, Atash. There is no god but God, and you are his Prophet.”

Professor studied Shah’s expression. The man did not seem particularly overjoyed by his calling. “The others came here? Muhammad? Jesus?”

“From Adam at the founding of the world, to Bahá'u'lláh.”

Professor recognized the name taken by Mírzá Ḥusayn`Alí Núrí, a Persian Muslim from the 19th Century, who claimed to have received a new revelation from God and subsequently founded the Baha’i religion.

“All came here?” Shah repeated. “Yet there is no mention of this place in any of the Holy writings.”

Gabrielle was visibly displeased by Shah’s refusal to simply embrace his new role in the divine plan. “You are the Prophet. It is for you to decide what you will share, but just as you have questioned the seemliness of the manner in which the revelation was given, know that there are others who would also do so. They might demand to see it for themselves. That is why the prophets of old did not reveal their journeys. And…” She gestured in Professor’s direction. “It is why he can never leave this place.”

“That’s right,” Professor said, sarcastically. “You can’t have me telling the world that your religion is complete hogwash, and that the Wizard is really just a machine being run by a crazy old guy hiding behind a curtain.”

Shah stared at Professor. “A cover up.” It was a statement not a question, but there was nonetheless an undercurrent of disbelief.

Gabrielle’s frown deepened and when she spoke, there was no hiding the disappointment in her tone. “You are the Prophet of God. Start acting like it. He is an unbeliever. His presence here is sacrilege. An affront to God. You know what must be done.” She paused a beat. “It is not necessary for you to do the deed, Atash. Simply give the order and it will be done.”

For several seconds, Shah just stared at the gun in his hand. “No,” he said finally. “I’ll take care of it.”

Then he aimed the gun and fired.

TWENTY-NINE

The world opened, and Jade saw everything.

They came in vessels — spaceships, she supposed — that, to the primitive bands of hunter-gatherers who occupied the area, must have seemed like great monstrous beasts or spirits of the sky. With elongated skulls and unblinking black eyes, pale gray skin, long smooth sexless torsos, their appearance was remarkably like the images that would, in later years, inform descriptions of demons and much, much later, the entities known, to those who believed in such things, as “grays.”

Extraterrestrial visitors. Aliens.

The grays paid little heed to their human neighbors. The nomadic people might have been insects, scurrying about, unnoticed by the alien workmen, whose attention was consumed with the task of hollowing out the great tower, which would one day be called Bell Rock. When they excavated a cavity using tools that were beyond even Jade’s imagination, they used the overburden to fashion durable concrete with which to build structures and the machinery of the Vault. Jade had no sense of how many years passed while they labored. Decades. Perhaps centuries. When the machine was complete they turned their attention to the primitive humans, and Jade saw now that the grays had not been ignoring them after all, but merely making preparations. The Vault was, in fact, just the first phase of an experiment, and the humans would be, in scientific terms, the dependent variable. Lab rats.

To maintain the purity of the experiment, the grays took some of their subjects and modified them, imbuing them with enhanced intelligence and abilities with which to carry out the programming written into their DNA. Physically, they appeared no different, save for jet black eyes and smooth skin that seemed not quite fully formed — a blank canvas on which they might paint the faces of others whom they wished to impersonate as they went forth into the world to do their part of the great experiment. They, and all their scions through the ages, were the Changelings.

The experiment was a thing of simplicity. A man — a shaman or in later years, a priest — would be shown to a special place — the Hypogeum, or one of many such sites scattered across the world, whereupon they would be compelled to make a pilgrimage to this distant land, and there receive the vision. What exactly that vision would entail depended as much on the man and his preconceptions as it did on the machinery of the vault, for the great machine did not implant new ideas so much as stimulate connections between disparate memories and beliefs. That was, in fact, the whole point of the experiment, to see what wonders these men might accomplish with just a gentle nudge every thousand years or so.

Roche had not been far off the mark with his belief that all of reality was merely a holographic simulation being controlled by otherworldly entities.

It was not given to Jade to know if the grays continued to monitor their experiment, if the tales of demonic visitation and UFO sightings across the gap of history were actual encounters with the grays, or merely the product of random infrasound frequencies stimulating ancestral memories. She suspected the latter, just as she suspected that the experiment had gone awry over the millennia, the way a message handed verbally from one person to another and then to another got distorted with each telling. The Changelings, though bound to their purpose by genetic chains, continued to guard the vault, dissuading those whom they deemed unworthy of receiving the vision, men like Archimedes, who in their genius, might have envisioned a new way forward, a world built on logic and rationality, rather than superstition. Similarly, they used their chameleon-like abilities to infiltrate the halls of power, making subtle adjustments but when necessary, triggering upheavals and wars to reset the balance. Their signature was writ large across the tableau of history. Roche had seen it, though imperfectly, and it had ultimately cost him his life.

Jade’s view was crystal clear. She wondered what that seeing would cost her.

As her awareness returned, she caught a glimpse of what was transpiring less than a hundred feet away. Shah had left the vault’s interface, a room similar in design to the Hypogeum, situated right above the orb-shaped chamber where Jade now was. The spherical room served the same function as the lens in an eyeball, focusing the infrasound created by the machine and directing it into the interface. Shah had received a vision too, but of what, he alone knew. Now, he was with the others, the Changelings who had been waiting for him. Waiting for all of them.

They’re going to kill Professor.

The thought snapped her back into herself. She needed only a fraction of a second to reorient herself, and another to find the wall with an outstretched foot in order to begin climbing back to the balcony. Urgency gave her a strength that had been lacking during her earlier mishap on the rope. A few moments later, she was able to reach the balcony rail and pull herself over.

She wrestled out of the harness and sprinted for the stairwell. She had no doubt of where it would lead. The vision had shown her the way forward and now she was intimately familiar with the stairwells and tunnels and passages of the vault. What was not as clear was what she would do when she arrived at her destination.

As she neared the top of the stairs, she slowed to a walk and flicked off her flashlight so as not to betray her approach. She could hear their voices clearly now, not a trick of acoustics but rather a matter of proximity. The woman Changeling was trying to convince Shah to kill Professor in order to hide the existence of the vault from the outside world, and from the sound of it, Shah was about to do it.

She saw shadows on the curving walls of the passage. A few more steps, and she would be able to see the bodies who cast them.

Her foot struck something. She froze, wincing at the clatter, but evidently no one in the passage beyond heard it. She looked down and saw what she had kicked. A semi-automatic pistol. There was a second one, still tucked in a clip-on holster, a few feet from the first. She took both, clipped the second to her belt, then eased the slide back on the first to ensure that a round was chambered. She still wasn’t sure how to save Professor, but at least now she was had some equipment to work with.

Before she could take another step however, the sound of a shot assaulted her ears. The close confines of the passage amplified the noise and set Jade’s ears ringing deafening her even to her own cry of alarm. She ran forward, aiming the pistol ahead of her, ready to avenge Professor’s death.

There was a second shot, the sound considerably muted after the first, and then a third as Jade rounded the bend. Her eyes went immediately to the man lying motionless on the floor.

“Professor!”

Blood was fountaining from his chest, soaking his shirt and staining the floor beneath him.

So much blood.

She did not let her gaze linger on him, but turned to look for the gunman and take her shot before he could think to shoot at her. Her attention fixed immediately on Shah who held the smoking gun. He was turned away from her, presenting his back as a target at point blank range. She could not miss.

But then another man dropped to his knees beside Professor. It was Jordan Kellogg. His hands were clutching his chest, trying in vain to stem the torrent of red flowing from a pair of wounds near his heart.

That was when Jade realized that the other dying man was not Professor, not her Professor, but the Changeling who had attempted to impersonate him. There was no uncertainty about this identification. The stricken man still wore the same clothes she had seen him in during their brief meeting in Malta. He even had Professor’s watch and fedora, though the latter item had rolled away.

The real Professor was still standing, unhurt, a few steps away from both Shah and the two Changeling men. He saw Jade and his eyes went wide in a mixture of surprise, fear, and relief. He shouted to her, words that she could barely make out. “Jade! Look out!”

Jade was not sure exactly what he was warning her about. Shah appeared to have come through for them, turning on the Changelings and sparing Professor. She swung the barrel of the pistol around, aiming it at the dark-haired woman in sunglasses who seemed completely oblivious to what had just occurred. That was when Shah finally noticed her. He spun around on his heel and aimed his pistol right at her.

Jade was caught off guard by the suddenness of this apparent reversal, but her nerves were already primed for action. Reflexively, she brought her own weapon to bear on him. In the brief instant that followed, she read his intention. His was not a reflex action brought on by her unexpected return. He meant to kill her.

He fired.

She fired… Or would have if Professor had not caught her in a low tackle that not only rushed her into the darkness behind them, but also removed her from Shah’s field of fire. In the tumult that followed, Professor managed to relieve her of the unfired pistol, whereupon he rolled onto his back and pumped several rounds in Shah’s direction. Jade wrestled the second pistol from it holster, but Shah was already gone, fleeing back down the rotunda. The woman was gone too, either having fled or in Shah’s company.

Professor looked over at Jade, panting to catch his breath, just as she was. His lips moved but she couldn’t make out what he said, so she answered simply, “Hey.”

He flashed her a goofy grin then got to his feet, hands gripping the pistol, and started forward. “Shah!” he shouted.

She heard that just fine, but no answer was forthcoming. “What the hell is he doing?” she said.

Professor returned an uncertain headshake and kept moving. He said something, stay behind me, or keep your head down. The ringing in her ears was gradually subsiding, but he was turned away from her and whispering. She hefted the pistol, muzzle pointing up, and followed.

They crept along at first, but then quickened their pace when it became evident that Shah was not waiting to ambush them. When they reached the doorway connecting the rotunda to the landing outside, Jade glimpsed movement on the spiral staircase overhead; Shah and the woman ascending but making slow progress, probably because the latter was being dragged along unwillingly.

Professor shouted again. “Shah! Let’s talk!”

Shah’s answer was a fusillade of rounds fired down the center of the shaft. The angles were all wrong for him to hit them, but the resulting spray of stone chips and bullet fragments drove Jade and Professor back through the opening.

“Idiot,” Professor rasped. He looked at Jade. “You okay?”

She laughed despite herself. “Stupid question.” At least I can hear again, she thought. “You?”

“Better than my evil twin.” He nodded in the direction of the stairwell. “What do you think got into Shah?”

Jade bit her lip guiltily. “You remember how I had to make a deal with him? Well, the deal was that if we found anything that might call the origins of Islam into question, I would let him destroy it.”

Something like anger or disappointment flickered across Professor’s face, but before he could voice his disapproval, Jade went on. “I didn’t have much choice. There was literally no one else I could trust. At least with Shah, I knew where I stood. And he did help. I just didn’t think we would actually find anything here that would fit the bill.”

“You really blew that call.” Professor’s demeanor softened a little. “I suppose given the circumstances it was the right thing to do. And I am grateful that you were willing to do that for me. So what do you think pushed him over the edge?”

“This place. It’s like a gigantic infrasound hallucination machine.” She decided now wasn’t the time to go into detail about what she had seen in her own frequency-induced vision.

Professor nodded slowly. “The Changelings told him that Muhammad and all the other prophets revered by Muslims came here to receive visions from God. I suppose, from his point of view, something like that — an alternative version of events that doesn’t agree with what the Quran teaches — could be construed as blasphemy.”

“And since he can’t destroy the vault, he decided the next best thing was to kill all the witnesses. The Changelings and us.”

Professor nodded. “There’s only one way out of here. If he’s up there waiting for us, we’ll have to shoot it out. But he’s already fired eight rounds. I counted. That means he has seven more, eight max if those Changelings kept one in the chamber, which I doubt. He has no training, no fire discipline. All we have to do is make some noise and get him to shoot off the rest of that magazine. Then we’ll leave on our own terms. Over his dead body if necessary.”

“I’m remembering the last time you counted the bad guy’s bullets. It didn’t end well.”

“Very funny. This time, I know he doesn’t have any extra rounds. Besides, you’re hardly in a position to be questioning my judgment.”

Jade thought better of replying. She gestured to the doorway. “Lead the way.”

He flashed a grim smile then stuck his head out. “Shah! We’re coming for you!”

There was no answering fire, so he circled the landing and started up the steps. Jade stayed close on his heels. The stairs were familiar to her, the memory of traveling them implanted during her vision, but it wasn’t until she was halfway up that she realized that she had been here before, actually as well as virtually. She had fallen through the central shaft after solving the ring puzzle and opening the door to the vault.

The memory nagged, a dire warning of a danger that she couldn’t quite wrap her thoughts around. Not Shah… Something else.

The stairs. Something about the stairs. Where did they come from?

One moment, she had been in the submerged chamber, sliding the pieces of the ring puzzle into place. The next she was falling, caught in the rush of water pouring down through the midst of the steps.

The steps….

In her mind’s eye, she saw it happening, like a video playing in slow motion. The last piece of stone sliding into place, the rings completed, and then….

And then the sphere began to move. It had seemed random from her perspective, trapped in the flooded chamber, but it was anything but. The movement of the sphere was as precise as clockwork. As was what happened next.

The sphere had opened like the petals of a flower, the individual tiles shuffling and rearranging to form the stairs that led down to the vault itself. The unfurling had of course triggered the flood that washed Jade away, and that indeed had been somewhat more chaotic, but the unfolding of the sphere chamber had been exceedingly exact. When the puzzle was solved, the door opened. Simple as that.

And what happens when the door closes?

“We have to get off these stairs.” She said it once, too softly to be heard. Then repeated it again, louder so that Professor could hear.

She saw the unasked question and knew that if she didn’t at least try to explain, precious moments that might mean the difference between life and death might be lost.

“Once he reaches the top, the lock will reset. These steps will disappear.”

Professor seemed to grasp the broader point. “And we’ll be trapped in here.”

Before Jade could respond to his hasty conclusion, Professor leaned into the stairs and poured on a burst of speed that she was hard-pressed to match. She heard him shout again, and then the noise of multiple reports filled the shaft. She threw herself flat as stone chips and dust filled the air. Jade tried to count the number of rounds fired, but it was difficult to distinguish one shot from the next, to say nothing of differentiating Professor’s gun from Shah’s.

After a few seconds, the shooting stopped. Something flashed through the air, hit the wall behind Professor and rebounded away, skittering across the steps and ultimately sailing out into the abyss. It was a gun. Shah’s gun. One less thing to worry about.

She raised her head and caught a glimpse of Shah running, still dragging the dark haired woman behind him. He was on the far side of the shaft, nearly at the top of the stairs, and even though Professor was closing the gap, it seemed unlikely that he would be able to catch Shah in time to stop him from slipping through the exit passage. Nevertheless, Jade’s sense of the place told her that close might be good enough. The ancient architects of the vault had designed the lock room to function like the automatic doors at a supermarket. As long as Professor was within reach of the exit, the mechanism would not reset.

Suddenly the stairwell erupted with another blizzard of gunfire. The incoming storm of bullets and debris was so intense, it forced Jade to retreat back down the spiraling steps until she was almost directly below the exit, out of the shooter’s line of fire.

Professor scrambled back down to her position. “Son of bitch brought reinforcements,” he growled. Before she could think to ask what Professor meant, he pointed at the pistol in her hand. “Let me have that. I’m out.”

She passed it over. “How many?”

“Too many. But unless you know of a back door, the only way out of here is—”

Before he could finish, an ominous grinding sound filled the shaft as the steps on which they were standing, and all the others above and below, began moving.

THIRTY

Shah crawled down the cramped passage, one hand stretched awkwardly back to drag Gabrielle along. Though he had only been in the vault a short while, he was desperate to be in the open, breathing fresh air again. Perhaps having the sky above him again would help to purge his memory of the things that had been revealed to him, but somehow he doubted it. The truth would haunt him to the end of his days.

Gabrielle was sobbing behind him. That was something new. In all the time they had worked together, all the intimate moments they had shared—all a lie—he had never seen her cry. Her despair comforted him. She had brought his world crashing down; a little suffering was the least he could hope for.

He would put an end to her misery soon enough.

The jihadists’ arrival could not have been more timely. Though he had only been able to give them vague directions in his text messages, the men had correctly divined the significance of the little cave in the sheer face of Bell Rock and rigged their own belay lines in order to transport the material he had requested and expedite his escape. Two were waiting in the niche at the end of the passage. The others were bringing up the rear, wriggling through the passage behind him. Shah did not know if Jade and Professor would attempt to follow, but if they tried, it would only hasten their inevitable appointment with fate. He could not allow them to leave the vault.

He emerged from the cramped passage and hauled Gabrielle forward. She went sprawling and would have tumbled out through the mouth of the cave if the two jihadists, uncertain of his intentions toward her, had not caught her.

Shah did not actually know why he had brought her along. He should have left her behind, both as a practical matter and a moral one. She was the enemy, his enemy and the enemy of Islam, and she always had been. Every word she had uttered, and a thousand implicit promises never spoken, were false. Everything they shared, a deceit. And yet, here she was, still alive.

What power does she have over me?

Gabrielle raised her head. She had lost her sunglasses during their transit to the surface. Her tear streaked eyes staring at nothing. “Atash,” she wailed. “What have you done?”

Shah choked on his disbelief. “What have I done? I?”

Her head turned toward the sound of his voice. “You have everything. You have seen. You are the Mahdi. The Prophet returned. I did this for you.”

Rage in Shah’s chest like steam in a geyser. She actually believed she had done him a favor. “I guess you never really understood me at all then.”

He turned to the nearest jihadist and held out his hand. The man placed a pistol in his palm. “Did you bring what I asked you to?”

One of the others — the young man from California, the geologist’s son — stepped forward. “Only about fifty pounds. All I could get my hands on.”

“It’s enough.” He pointed up to the passage leading into the vault. “Place it there.”

As the jihadists set about their task, he placed the muzzle of the pistol against the back of Gabrielle’s head. Before he pulled the trigger, he leaned close and whispered in her ear. “I didn’t see anything.”

THIRTY-ONE

In a matter of seconds, the stairwell transformed into something else. The blocks that had arranged themselves in an orderly spiral began to shift and slide, changing position with mechanical precision. Some disappeared altogether, sliding into recesses in the wall, their purpose served, while others protruded further, tilting and rotating, rising or falling, reassembling the spherical chamber that was the entrance to the vault.

Professor grabbed Jade’s arm and was about to start up the treacherous steps but Jade pulled free. “No! Down!”

“We’ll be trapped in here!”

There was no time to explain to him that trapped was preferable to being dumped down the full length of the vertical shaft or crushed between blocks of stone, so she let her actions do the talking. She turned away from him and started down the stairs, or rather tried to. Negotiating the descent was part fun-house, part obstacle course. Every step took her from one moving surface to another and she wasted precious seconds with each move just to keep her balance. They were nearly clear of the blocks that were rising to form the sphere. Below, the steps were simply retreating into the walls, all the way down the landing. If they could not reach the passage back to the rotunda before the steps vanished, they would fall into the cistern below, as Jade had done earlier, but from more than twice the height.

“Shortcut!” Jade shouted. Instead of trying to corkscrew her way down the rapidly disappearing passage, she launched herself out across the chasm, landing on the lower steps on the opposite side. Her momentum, along with the movement of the block upon which she landed, carried her into the wall, but she pushed off and jumped again, arcing across the ever-widening gap to the next level. Professor had evidently decided to trust her judgment; he too was caroming back and forth from one side of the spiral to the other, but as the blocks slid back into the wall, the distance across the chasm increased while the potential landing zones continued to diminish.

Jade saw the landing, what little was left of it anyway, ten feet below. The wedge-shaped blocks, which had caught her climbing rope during her initial fall, were in full retreat — less than six inches remained, and even if by some stroke of luck she managed to make the nearly twenty-foot leap and stick the landing, the blocks would be gone completely before she could reach the opening to the rotunda, so she decided to skip a step and go straight for her goal. She turned forty-five degrees to aim herself at the passage, then jumped straight up, planting her feet against the wall and pushed off like an Olympic swimmer making a turn.

Yet, even as she straightened her legs, propelling herself out into space, she knew in her heart that she was going to fall short of her target. The difference would be miniscule, just a few inches, but those inches would make all the difference. She would slam into the wall just below the entrance, and then fall once more into the cistern below.

The open passage taunted her with its nearness. She knew she would never be able to reach, but she stretched her arms out anyway. A thought flashed through her head. I might survive the fall if I don’t get knocked out hitting the wall.

Something moved, right above her. It was Professor, hurling himself across the gap, just as she had done. She felt his hand close around her arm and then….

The impact with the wall knocked the wind out of her. She thought she would fall then, but instead, there was a sharp pain in her shoulder as all her weight settled beneath the hyper-extended limb. Her mouth opened to issue an involuntary cry, but she had no breath to scream.

She hung there, pressed against the wall, hanging by one arm. Her immediate impulse was to claw her way back up the rock, but every time she tried to move, the pain in her shoulder spiked. If she didn’t relieve the pressure, her arm was going to be ripped from its socket.

She glanced up and saw the hand that had saved her, Professor’s hand, wrapped around her wrist. He lay flat in the opening to the passage, head and shoulders protruding, teeth clenched with the exertion of holding her.

He reached down with his free hand, and she reached up, stretching more than she would have believed possible, and somehow grasped his outstretched hand.

Suddenly she was moving again. The pain in her shoulder was nothing to the relief she felt as he lifted her to safety.

Her breath returned with a gasp and for nearly a full minute, all she could do was lie on the stone floor, enjoying the feel of something solid beneath her.

“Okay,” Professor said, at length. “We’re alive. I haven’t decided if that’s the good news or the bad news.”

“The good news,” Jade said, “is that we aren’t trapped.” She tried to sit up, winced at a fresh stab of pain in her shoulder.

“Don’t tell me you saw a back door? That would have been nice to know.”

“I didn’t know,” she retorted. “Not at first. But those Changelings that were waiting for us? They didn’t come in the front door. And I got a look around when we were separated.” She did not reveal that her look around had been mostly a virtual tour. “I know where to go.”

“Well, why didn’t you just say so?” He got to his feet then squatted beside her and began probing her shoulder. “Still attached,” he declared. “Just a muscle strain. We’ll get you some SEAL candy — you mere mortals would call it Motrin — and you’ll be ready for the Olympic gymnastics team in no time.”

She laughed despite herself. “That’s good to know, because this archaeology thing is wrecking me.”

He helped her to her feet and then gestured for her to lead the way. She backtracked into the rotunda, and soon happened upon a pair of bodies — Kellogg and the man Jade had called Not-Professor.

“I wonder who they really were,” she murmured. “You think the real Jordan Kellogg is in a landfill somewhere?”

Professor’s eye twitched. “If he’s lucky.”

His tone was enough to keep her from asking him to elaborate. She knelt to retrieve his fedora and placed it on his head. “There you go. Back in business.”

That was enough to bring a sparkle of humor back to his eyes. He retrieved his watch from the dead imposter, and then riffled through man’s pockets, reacquiring his passport, wallet and phone. “Now I’m back in business.”

“Want to see what he really looks like?”

“Nope. I just want to find that back door and get the hell out of here.”

Jade shone her light down the passage and moved toward the stairwell she had used to reach this level of the vault from the chamber where she had received her vision. The stairs did not ascend any further, but there was another opening on the inside wall of the rotunda, a passage that led to the chamber Jade thought of as “the interface.”

She pointed to it. “We have to go through there. But I should warn you, you’re going to see some things.”

“Yeah? Like Biblical stuff?”

Jade shook her head. “It doesn’t work like that. What you see kind of depends on what you take in with you.”

He narrowed his gaze at her. “How do you know that?’

“That’s how they built it.”

“They?”

“The aliens,” Jade said, feeling inexplicably foolish. “The grays. The extraterrestrial astronauts that Stillman was always going on about.”

“You saw them?”

“Yes. And I also found a bunch of their skulls.”

He nodded slowly.

“Don’t patronize me,” Jade snapped.

Professor raised his hands. “Sorry. Actually, I’m a little curious to see what this thing will show me.”

Jade gave him a hard look, but his skepticism was already undermining her own certitude. What if everything she had seen was just the product of her own preconceptions? Was her vision of alien engineers any more reliable than the angels or devils that Shah and all the self-styled prophets before him had seen?

But in the Hypogeum, I saw this place. That wasn’t a lie.

A tremor rippled through the floor and Jade felt a subtle change in the air pressure. Professor raised his head sharply, turning to look back down the passage. A moment later, a loud thump reached her ears.

“What the hell was that?” Jade asked.

He turned back to her, his expression now full of urgency. “That was an explosion. Shah’s terrorist friends just blew the entrance.”

Another violent shudder shook the passage, accompanied by a noise as loud as a gunshot, and Jade was thrown to the floor. Jagged cracks, like lightning bolts, appeared on the walls and ceilings, vomiting out a miasma of dust. Professor managed to stay on his feet. He seized Jade’s arm, triggering a nauseating wave of pain in her injured shoulder, but she fought through it, got up and staggered through the doorway.

The floor heaved and then began to tilt crazily, like the deck of a ship climbing the face of a rogue wave. Pieces of stone and concrete tumbled down around them. Jade threw her good arm up as a shield and plunged forward as the vault began coming apart all around them.

The Interface looked nothing like her vision of it now. Although the initial blast yield had been relatively small, it had thrown a monkey wrench into the precisely engineered machinery of the vault. The infrasound amplifier had become nothing more than a roiling tangle of jagged stone, slumping down through the center of the cylindrical tower.

“There!” Professor’s shout was barely audible in the tumult of grinding rock, but Jade heard and followed his pointing finger to their salvation, a rope ladder hanging down in the center of the chamber and rising up into the gloom overhead.

It seemed impossibly far away.

“We’ll never—”

Professor let go of her arm and scooped her off her feet. Before she could protest, he heaved her out over the center of the stone vortex. Something — the rope! — slapped against her face and she threw her arms around it, hugging the woven fibers even as she started to fall. The friction burned her face and chest, but she squeezed tighter and managed to slip her arms between the rungs.

The rope jerked taut with a bone-shaking abruptness and then she was hanging again, dangling above the swirling whirlpool of debris.

The ladder shuddered again, as if trying to shake her loose, and she saw Professor above her.

“Climb!” he shouted, and then he was moving, scrambling up the rungs.

Jade kept hugging the ladder to her, certain that if she let go, even to get a better hold, she would lose her grip and fall into the meat grinder below. She tried to find the rungs with her feet, but felt only empty space.

Another thunderclap shook the mountain, and what little remained of the interface and the surrounding tower dropped away. For a fleeting instant, Jade saw the vast cavity inside Bell Rock — the towers and aqueducts and air channels crumbling like an elaborate house of cards.

Then the shockwave hit. The Vault breathed its last, a blast of heat that buffeted Jade, propelling her up even as it engulfed her in a cloud of scalding steam….

And then it was over.

She lay beneath a sky full of stars. The smell of crushed earth was still in her nostrils, but the air was clear.

Professor lay beside her, and between them was a heap of rope, the ladder that Jade was still clutching. Professor had made it to the top and then hauled up the ladder — and her — like a fisherman dragging in his net. He had saved her.

She made a mental note to thank him.

To her left, a narrow fissure marked the Changeling’s secret entrance to the vault, or rather to the cavern where the vault had once stood. She did not need to look into it to know that the vault and all the answers it might have held — secrets or illusions — were gone forever.

Maybe it was better that way.