CHAPTER 76
“I might know what Mack has,” Rabinowitz said, shouting over the drone of the engine.
He sat beside Sturman on one of the bench seats in the pontoon boat, opposite Val and Eric. The vessel was almost identical to the one Mack had rented, but in much worse shape. It had been anchored in a shallow private lagoon. Clive had found the keys in a shed near the house onshore, and taken them without bothering to see if the “friend” who owned it was home. He was now at the helm.
“What do you mean?” Val said. She thought Rabinowitz was doing quite well for someone struck by lightning a day before, having only received minor burns and gone briefly unconscious. He’d come reluctantly when Sturman called him. Wits was another Navy guy, and a technology and weapons expert. He might know how to disarm a device, if Mack actually had one down there.
“Tell her, Wits,” Sturman said. “All of it.”
Rabinowitz rubbed his face. “Well, you said he might have found a Navy ROV twelve or thirteen years ago. Our testing facility supposedly lost one around that time. And its rumored payload was what we called a DCD. Short for ‘Deployable Cavitation Device.’”
“What did it do?” Val said.
“I really shouldn’t be telling you this.”
“Please, Tom. We need to know.”
He winced as ocean spray came over the side and wet his face. “It was supposed to be some bad-ass sort of sonic weapon. But I never worked with one, or even saw one used. I wasn’t even sure it was real.”
Eric said, “The Navy actually lost an ROV, and a weapon attached to it?”
“They were both experimental. The details are classified, but rumor has it the ROV’s guidance system failed after it retrieved a DCD, during a test run near the Andros wall. Nobody knew where the submersible ended up. But it disappeared in relatively shallow water—just a few hundred feet. Since we never found it, some of the brass supposedly suspected it had been stolen.”
“Cavitation,” Val shouted. “Isn’t that what happens when a boat propeller generates bubbles underwater?”
Wits nodded. “Water produces more friction than air, so drag creates vapor cavities on fast-moving objects underwater. Basically, lots of small bubbles. Supercavitation technology has actually been in use for years, to address this problem. It allows our torpedoes to travel hundreds of miles per hour, by producing streams of bubbles from their noses that surround them in a coating of air. Presto. No friction.”
“But it can also be used as a weapon?” Eric said.
“The idea is to use sonar itself to destroy things. A cavitation weapon requires two or more devices, set a few hundred feet apart, which create acoustic beams. At their intersection, the beams generate an intense pressure bubble and incredible heat. With enough power, you can essentially use pure acoustic energy to destroy targets.”
“Seriously?” Sturman shouted.
“Seriously. I won’t say much more, other than that this technology is real. But the DCD was only a rumor. Because it supposedly could create a destructive cavitation field all by itself, without the need for another device. It supposedly somehow overcame that, with two closely joined emission devices that could merge their beams effectively, even from a narrow angle.”
Clive slowed the motor. “We almost dere.”
Mack moved deeper into the cavern. In the beam of his dive light, he could see that here it became a sideways fissure, a split in the ancient limestone that ran laterally off the main shaft.
Arming the weapon had been simple enough. Years ago, back when Breck had brought the deceptively heavy device ashore that night, they’d spent some time looking it over, their beers on the ground beside it. Breck said he’d help set one before, as a Navy freelancer, but had never seen it actually go off. It had a benign enough appearance, consisting of twin toaster-oven-sized cylinders of metal affixed to one another, side-by-side, the way double air tanks are mounted for diving. But Breck had explained it was a state-of-the-art deployable weapon.
When at the inland blue hole a week later, he’d showed Mack how it worked. It operated off a digital timer, and was intended to be set stationary, by an ROV or Navy divers, and directed at its target—in that case, the far side of the blue hole they’d brought it into. Fifty feet under, they’d placed it on a ledge and set the timer for fifteen minutes, and then quickly surfaced. For good reason. When it had gone off, sending a sonic pressure wave against the far wall, there had been no loud detonation. But a small tsunami rose from within the hole when a submarine slab of rock blasted free on the other side of the pool, displacing the water around it.
Apparently, the device was designed to destroy mines and bridge supports, or rupture ship hulls. All using sonic waves.
Mack needed to hurry. He’d already been down for almost an hour, and this time he’d set the timer at the surface—for ninety minutes—in case something happened to him before he could complete his mission. He’d figured it would give him time to get down here, to find the beast’s lair. To position the device. But not so much time that others might have the chance to figure out what happened, follow him down here if he didn’t come back.
He knew he might not have enough time to safely resurface. But that was okay, as long as he found the den first, and the device still had enough power to fire one last time.
He had some idea what an octopus’s midden would look like, or the pile of debris it might create outside its lair. He’d seen what must have been older ones on DORA’s recordings from deep in the bottom of this pit. He hoped the old whore hadn’t laid her eggs deep down there, where he couldn’t reach, since he still hadn’t been able to locate the new den. If he couldn’t find it before the timer ran out, he’d decided he’d just find a ledge, and aim the device down the center of the main shaft, then swim like hell for the boat.
The resort schematics had provided exact coordinates for the mouth of the outflow pipe, and using a GPS to estimate where it would be before he entered the water, he’d located it in a side tunnel branching off the Bottomless Blue Hole. One they hadn’t been in before. The metal grate that had guarded its opening had been torn free and lay ten feet away, on the bottom of the cavern, now bent and twisted. He’d sucked in a breath of air, a single thought entering his mind then:
She’s in here somewhere.
He’d started at the end of the pipe, and began to search carefully through the darkness. The light would betray him, but at least he was wearing a rebreather, to give him extra bottom time and not give off air bubbles that would reveal him too soon.
Now, after investigating two smaller tunnels that yielded nothing, he entered the broad horizontal fissure. He moved slowly, taking deep, measured breaths. He stopped.
Ahead of him was a barricade of rock, with a cinder block and some other rubbish resting on top. The objects were free of excessive barnacles or other growth, which could only mean they’d been added recently. He finned toward the rock pile, clutching the heavy device in both hands. Underwater, its weight was manageable. But it dragged at him, trying to pull him down deeper.
When he reached the berm-like heap, he set the device down and pulled himself over the rubble, staying low, on his belly, like a soldier peering out at the enemy from a foxhole. At the crest, he took a deep breath, preparing himself, and shined his light over the top, into the darkness.
He’d found it.
There was no octopus looking back at him in his beam of light, no great tentacles squirming inside the protected nook, but what he was seeing he’d never seen before. Nobody had. He knew he was looking at the brood of something enormous. Looking at her spawn.
He swept the light around the cavern, which was about the size of a basement. He waited. Nothing happened. But he knew she might still be here.
He was as sure as he could be that she wasn’t inside. It was time. He steeled himself for the crush of her tentacles as he lifted the weapon off the bottom and dragged it over the embankment. Moving to the edge of the nearest targets, he shoved the device into a recess in the rock, where it would be less visible, and directed its business end toward them.
Here’s a little birthday present for the kids.
He checked the timer one last time. It was still counting down steadily:
31:46 . . . 31:45 . . . 31:44 . . .
He turned away from it and kicked for the shaft. He cleared the barricade and covered another twenty feet, forty, sixty. Swimming down the broad, flat-ceilinged tunnel as fast as his crippled leg would allow. Nothing grabbed him. Finally, he saw a bright light ahead. He was nearing the main shaft.
He checked his air supply. He still had plenty to make it back. He could even make a safety stop. He hadn’t even considered what he’d do if he made it out of here. He’d have to run, because the US government would be after him. Maybe he’d spend a few years in South America, or the Virgin Islands. He smiled at a thought: Maybe he wouldn’t be seeing Breck anytime soon, after all.
The thought quickly faded. Because he wouldn’t be seeing Breck again. Not ever. To see him again, there would have to be a heaven. A God. After seeing what had happened to his friends, even to his enemies, in the war, how could he believe there was a God?
He heard something. Something artificial. A clanging, a ceaseless ringing, resonating down through the dim water.
Mack knew immediately what it was. A sound he’d heard so many times, one that carried well underwater, and that he’d often made himself to get the attention of other divers. Someone was here. In or above the shaft of the hole. They were trying to get his attention. And his niece likely was with them.
It was too late, though. The device was set to go off in less than thirty minutes. He didn’t know how to stop it.