Such crafts were meant to ride up onto land, even maneuver over shores on those air cushions. An LCAC could carry sixty tons of personnel and equipment, dumping hundreds of marines onto battle lines. But that wasn’t this boat’s main objective. It had a Type 96 battle tank, commonly deployed with such boats, sitting atop its deck, but this vehicle was capped by an armored dome stubbed with antennas.

  Monk guessed the tank had been modified into a drone, like all the other equipment aboard the LCAC. Its deck had been altered from its usual configuration of two fixed hull structures running parallel down either side with a gap between for tanks, landing docks, and infantry vehicles. All that was left of those twin structures was a pilothouse mounted forward-left. The rest of the deck was festooned with cranes and electromagnetic air-launchers.

  From those frames hung all manner of UUVs and AUVs. He recognized what looked like Sea Whales and Hidden Dragons, both of which were designed to operate autonomously underwater. Same with the rows of torpedoes, stacked like cordwood atop launching racks. In addition, fixed-wing and VTOL drones dotted the deck.

  Someone had transformed this LCAC into a fully automated attack boat.

  Earlier, Captain Stemm had helped Monk understand what was facing them. As a former Aussie naval man, he had recognized much of the technology, having followed the development of China’s AI-controlled naval forces.

  As they had watched helplessly from the bridge, the LCAC had launched an array of drones into the air and dumped more into the sea, forming a web of surveillance devices and armed weaponry all around. The Titan X had no choice but to surrender and allow an armed force to board the yacht. The LCAC had arrived with only a couple dozen marines. The other fifty commandos had come from the attack submarine that surfaced shortly after the LCAC’s arrival.

  The submarine’s sail still stuck out of the water, plying a slow circle a quarter mile off. It looked dejected and redundant. Beyond sending support troops, it was not needed. The LCAC and its complement of autonomous equipment had the yacht locked up tight. The AI-driven boat sat out there, crewed by maybe two or three. Its systems had clearly been designed to operate with minimal, if any, supervision.

  Captain Stemm wandered over, drawing the eye of two commandos, but they quickly lost interest. The gunmen knew the handful on the bridge offered no threat. The passing hours had further dulled their attentiveness.

  Stemm drew alongside Monk. “Radar is picking up a distant shadow to the west,” he mumbled under a fist as he feigned a yawn. “I know some Mandarin and overheard the bastards mention an LHD.”

  A landing helicopter dock.

  Monk bit off a groan and stared off to the dark skies to the west. Jagged bolts lanced through the low clouds, but the lightning failed to illuminate that threat.

  It was still too far off.

  “How long?” Monk asked.

  “At its current speed, it’ll be here in an hour.”

  Monk winced. He remembered the large V-shaped drone that had buzzed the yacht hours ago. It must have come from that larger ship. The Chinese were clearly not taking any chances. Whatever they were trying to hide or discover six miles under them had to be important.

  Since commandeering the yacht, the Chinese had been brutally interrogating the researchers, trying to discern how much they knew. It was likely the only reason the yacht hadn’t already been sunk.

  From his station, Monk could only watch impotently as the Chinese took control. He had flipped through the CCTV cameras that offered views into Science City. Bodies lay in the hallways, demonstrating the cost of resistance. Interrogators had beaten and maimed many others.

  Monk had noted a Chinese woman who appeared to be orchestrating this line of inquiry. Beyond her gender, she stood out because of the deference shown to her and the fact that she was the only one not dressed in camo. She wore a navy jacket with prominent epaulets over a white shirt and tie.

  Voices rose from the hallway.

  A contingent pushed onto the bridge, led by that same woman. She was flanked by a hulking brute in helmet and armor. His knuckles were bleeding and torn, marking him as one of the interrogators. The three commandos on the bridge snapped to attention.

  As Monk kept his gaze down, he heard her addressed, naming her and her rank.

  “Hǎijūn shang xiao Tse.”

  He gritted his teeth. Captain Tse. She must be the leader of this task force. He watched her sidelong as she made the rounds across the bridge. She crossed to the front and stared out the forward window, surveying all that she had subdued.

  Drones buzzed like gnats around the ship or sped by on fixed wings. The layers of ash on the water stirred with the tiny sails of her AUV and UUV weaponry. More patrolled deeper. She placed her hands on her hips, clearly satisfied with the view.

  She turned back around. Even shadowed by the brim of her hat, her eyes glinted under a straight line of black bangs. Her hair had been close-cropped and oiled flat to the sides. Her suit and shirt remained as crisp as her manner. The only blemish was a spatter of blood on her collar.

  Must’ve gotten too close to the handiwork of her bloody-knuckled interrogator.

  She consulted with that same man before coming forward to confront Captain Stemm, who had returned to the helm upon her arrival.

  She switched to English. “Captain Stemm, I understand that a submersible was launched shortly before our arrival. It was detected by our submarine and confirmed by those we spoke to aboard your ship.”

  Stemm swallowed and nodded. “It was a scheduled dive. That’s all.”

  “I don’t believe it was,” she said coldly, taking another step forward.

  Stemm tried to retreat, but he was blocked by the bulk of her interrogator, who pressed a pistol into the captain’s back.

  “According to the commander of our submarine,” the woman said coldly, “you all performed quite the noisy dance when it dropped—as if you were purposefully trying to mask its descent.”

  Stemm clamped his lips, refusing to respond.

  “I also heard of the discovery of a forest of giant coral and strange life down at the bottom of the trench where one of our boats sank. And rumor of a fissure opening up, swallowing that submarine and a large portion of the forest.”

  Captain Tse’s eyes shone with malice. Clearly her interrogator had done his job, and she now enjoyed lording it over her new target. From her stiff spine and thrown-back shoulders, she was carrying a four-ton chip on her shoulders. As a woman in the PLA, she likely had to claw her way to her current position, to be harder willed, more callous and cunning than her counterparts.

  Monk tried to find pity in his heart for her, but he pictured the bodies in the halls, the pummeled faces of the researchers.

  Screw that.

  Tse pressed Stemm for more details. “What did your submersible hope to find down there? I suspect it must be nearing the bottom by now. Were those aboard seeking to steal our new submarine’s technology or were they investigating the source of the quakes?”

  Stemm must have known it was futile to prevaricate with this woman. “The only interest we have in your nuclear submarine was how it pertained to those quakes.” He waved to the glower of flames in the distance. “Something must be done to stop this. You must recognize that.”

  “I recognize that when it comes to operations such as this, there should be only one captain.” She nodded to the hulking interrogator.

  The man shifted his pistol to the back of Stemm’s head.

  Monk took a step forward.

  The gunshot deafened and stung his ears.

  Captain Tse had stepped aside at the last moment—to avoid the spray of blood and gore as the round tore through Stemm’s skull. The man toppled to the floor as the rest of the crew gasped and fell back in horror.

  Monk’s fist clenched hard enough that his knuckles cracked under the strain.

  Tse looked his way, as if she had heard this. But she ignored the threat of his fist and stared him in the face.

  “Dr. Kokkalis,” she said. “We, too, will have a conversation. I am very much interested in DARPA’s involvement in all of this.”

  Monk refused to look away.

  So much for trying to blend in with the crew.

  Once again, the skill and handiwork of her interrogator had paid off. Too many of those aboard had known of Monk’s background—or at least the story that had been told to them. At present, as cut off as they were, he doubted the Chinese knew of his connection to Sigma. He had to hope this knowledge was kept from this woman for as long as possible.

  She waved to her commandos and barked orders. Two came forward with rifles and motioned for him to head toward the door.

  Before he left, Captain Tse had some last words and a promise.

  “We’ll continue our discussion shortly, Dr. Kokkalis.” She stared down toward her toes. “But first I must attend to another matter. One that I’ll address personally.”

  As Monk was marched off, he looked out windows to the LCAC. There remained one additional vehicle still aboard that attack boat. It hung over the stern. From its boxy shape and the sphere of glass at the front, there was no mistaking it.

  A deep-sea submersible.

  Only this one was being loaded with fat torpedoes. The weapons were likely engineered to operate at extreme depths.

  Monk glanced back to Captain Tse, who was looking down from the bridge at the same sight. He winced and turned his gaze miles down and sent a warning.

  Careful, guys, a new shark’s about to enter your waters.

  32

  January 24, 11:32 A.M. NZDT

  Six miles under the Pacific

  “Blowing ballast,” Bryan called out. “Slowing our descent.”

  Phoebe startled out of her drowse, shocked to find her chin resting on her collarbone. After being up all night and sinking silently and motionlessly through black waters for three hours, she had fallen into a light slumber.

  A few bubbles raced over the scallop of glass in front of her. As their descent slowed, she twisted in her seat. She didn’t even have to voice her concern.

  “Reading hundred-and-thirty rem out there,” Datuk reported, leaning to his sensor screen.

  “What about in here?” she asked.

  For this descent, Datuk had secured a portable radiation monitor so they could track the amount of their exposure inside. Insulated by the thick titanium and leaded glass, they had some protection, but it wasn’t absolute.

  He nodded. “So far, we’re still okay. Only picking up eight rem in the sphere. But you definitely don’t want to go swimming out there.”

  Adam spoke behind her. “I expected it to be worse by now. We’ve crossed nine thousand meters. Almost to the bottom.”

  Phoebe stared out the window and knew the radiation was bad enough. Far below, as they slowed their descent, the coral field remained a dark forest under them. Off in the distance, a luminescent shimmer marked the distant fringe of unaffected coral. The dead patch was easily four times as large as before.

  They continued sinking toward the center of that black hole.

  She knew the darkness directly under them was not due to deadened coral, but the mouth of the fissure that had opened. Bathymetric measurements showed the crack to be two kilometers long and a quarter as wide.

  She reached to her controls and pinged their sonar down into the depths.

  Adam noted her effort. “Any better luck?”

  She leaned back in her seat. “See for yourself.”

  On the screen in front of her, the Cormorant’s multibeam sonar showed the walls of the fissure below. While the trench bottomed out at ten thousand meters, the crack through the seabed delved far deeper. Its sides dropped away in sheer cliffs and broken escarpments. According to the gradient scale on the screen, those walls fell at least another two thousand meters, more than a full mile. Beyond that, it was impossible to judge how much farther it dropped. The image blanked out past that point.

  “I’m still getting nothing,” she said. “Something is either absorbing our sonar ping or keeping it from reflecting back to us.”

  “What could be causing that?” Datuk asked.

  Phoebe ticked off the possibilities. “Changes in water density, sonar from another source, noisy sea life.” She shook her head. “But none of that presents as a blank zone like that. We should still be picking up something. Instead, our ping simply vanishes.”

  Adam offered one frightening possibility. “Unless it’s so deep that our sonar failed to find its bottom.”

  “That would only happen if the bottom was hundreds of miles down.”

  Adam shrugged. “Do you have a better explanation?”

  She scowled and turned to Bryan. “Keep us dropping at this rate. It’s slow enough that if the radiation worsens, we can still head back up before getting overexposed.”

  Datuk reported from the back. “Hundred-and-eighty rem outside. Ten inside.”

  “Maybe the reason the radiation is less than we expected is because the Chinese sub dropped into a far deeper hole,” Adam said, clearly trying to support his theory. “Like I said before, water is a great insulator, especially at these pressures.”

  By now, the Cormorant had reached the top of the forest. They started to drop through its ruins. To either side, the coral spread in a dark ominous deadfall of shattered branches and toppled trunks. Nothing moved out there. Nothing shone or flickered.

  As if in respect for the graveyard they were passing through, a heavy silence fell over the group. Phoebe’s chest tightened. Her breathing grew harder.

  So much destruction.

  As they descended, the boles of the black trees steadily thickened. At a thousand feet in height, the surrounding forest rose as tall as the Empire State Building. She could only imagine the age of this coral field. Considering the slow growth of black coral, it had to be millions of years old.

  She gazed in awe at the majesty and mystery around her.

  After another ten minutes, the Cormorant neared the bottom of the forest. Here, the trunks were forty feet wide. They formed a giant colonnade around them, a dark cathedral six miles under the sea.

  “Here we go,” Bryan whispered as they descended past those roots and dropped into the fissure.

  “Two hundred rem,” Datuk noted.

  Adam leaned down to peer out his window. He studied the rock wall falling alongside them. “I’m not seeing anything growing on those cliffs.”

  “Not even algal mats,” Datuk agreed, peering past Adam’s shoulders.

  “The rock is still crumbling in places, running with trails of sand.” Adam straightened. “There’s no way this is some ancient crack that has been hidden by a bridge of coral. This is a new fissure.”

  Datuk nodded. “Definitely opened with the last quake.”

  Phoebe frowned at the view. “But why? And why right here?” She glanced over her shoulder. “It can’t be pure coincidence that it swallowed that leaking sub.”

  Datuk speculated, shrugging as if trying to discount his own words. “Maybe the clustering of quakes over the past two weeks was some attempt to get rid of the sub, an effort to drive it off. Then with that last spike in radiation, it’d finally had enough and decided to deal with it directly.”

  “If you’re right,” Adam challenged him, “what could do that?”

  “No idea.” He motioned to his sensors. “But I still find it odd how clean this water is after we passed through the brine layer. I’m not picking up any microplastics. The dissolved oxygen levels are through the roof. The salinity is way low. There’s a purity that makes no sense unless something is actively making it so.”

  Phoebe remembered pondering this mystery on their last dive, when she compared these vast coral fields to the Brazilian rainforest, one of the lungs on the planet’s surface. Was this forest the equivalent down here? Was it somehow keeping these seas pure, actively fighting to make it so? Did this support Datuk’s conjecture about something trying to physically rid the trench of the leaking, toxic boat?

  Bryan interrupted this reverie. “We’re about to break a record.”

  Phoebe turned to him. “What do you mean?”

  He nodded to the depth gauge on the screen that monitored their descent. The tiny, winged blip of the Cormorant on the bathymetric screen continued to fall along a gradient marked along one side.

  “We’re approaching eleven thousand meters,” he said. “Victor Vescovo holds the world’s record for the deepest dive. Just more than ten thousand, nine hundred meters. In a Triton-designed submersible like ours.”

  They all gathered closer and watched the Cormorant fall past that record.

  Tired smiles spread amongst them.

  “We should’ve brought champagne,” Bryan mumbled.

  Adam sighed. “Let’s hope we get a chance to tell the Guinness people.”

  Datuk asked an important question: “How deep can the Cormorant go?”

  “She’s been overengineered,” Bryan said. “Like most submersibles. She was designed to withstand pressures deeper than any known trench.”

  “Which means what?” Adam asked. “What is her crush depth?”

  “Fourteen thousand meters.” Bryan turned to them. “But that was based on lab tests, not a real-world challenge.”

  Adam stared down. “Looks like we’re about to test that.”

  Silence again settled over their group as they continued their plummet into a bottomless darkness.

  12:07 P.M.

  Daiyu climbed into the seat of the Qianliyan. The deep-sea bathyscaphe was named after a Chinese demon, whose name meant far-seeing eye. According to legend, he challenged Mazu, the goddess of the sea, but she tamed him and he became her guardian, protecting the depths of the seas.

  It seemed a fitting name, especially as she had chosen it when she and her team of engineers at the Guangdong Southern Marine Science and Engineering Laboratory had built its prototype. The PLA Navy had taken her early design and built this vehicle for their amphibious attack boat. She had inspected the Qianliyan while en route here and took great satisfaction in what she found, noting the PLA had adhered to her every engineering spec, down to the titanium and acrylic passenger compartment, which had been machined to within 99.978 percent of a true spherical form.