Deep Fire Rising - v4 (20 page)

The ship’s hull and superstructure had been crushed flat by the impact with the seafloor. This phenomenon wasn’t unusual. A falling vessel could approach twenty miles per hour by the time it reached the end of its plummet, and structural members weren’t designed for that kind of force. Yet the damage to the
Smithback
was much more severe than either Mercer or Jervis anticipated.

It was as if a giant fist had ground the vessel’s remains into the seafloor. The bow was buried deeply in the silt and her keel had fractured amidships. It was impossible to tell if she was listing because she had so completely collapsed. From the spec sheets Ira had had delivered to Mercer, he knew the
Smithback
had been ninety feet tall from keel to bridge. The hulk of twisted metal plates resting on the bottom of the Pacific looked no more than a quarter of that. She’d completely pancaked.

The light outside the submersible shifted as C.W. in his diving suit approached the wreck. “What happened to her?” he asked when he saw the extent of the damage.

“We’re trying to figure that out,” Mercer replied. “Let’s start with the bow and work our way back.”

“Roger.”

The nimble NewtSuit lifted away from the hull and swooped toward the front of the ship. Alan maneuvered
Bob
into place so the combined lights bathed the wreckage in a diffused yellow light. The two sub drivers moved as one as they made their way down the vessel’s length. The ship’s steel skin had wrinkled like an accordion and crossbeams from within the hull had punched through the metal like fractured bones. When they reached the amidships superstructure, Mercer had Alan take them as close to the ship as he dared. Every one of the six decks in the blocky superstructure had been flattened into the one below. Glass from the wheelhouse had exploded out onto the deck and glittered like gemstones. Near the stern they found where bunker oil leached from the hull in dark bubbles. There were only a couple of spots where air pockets vented into the sea.

“What do you think?” C.W. asked after they finished their inspection.

“If I had to guess,” Alan Jervis answered, “I’d say that she was fully laden when she sank and all the air escaped the hull as soon as she went under. That’s the only way she could be going fast enough to cause this much damage. What’s your take, Mercer?”

“Good theory but there’s a problem.” Mercer rubbed his jaw as he considered the implication of what he was about to say. “The
Smithback
was dead-heading back from Korea. She was empty. Her cargo decks encompassed more than a hundred thousand cubic feet. Even if her loading ramps had been somehow jarred open, it would take time to expel that much air. I think it was something else.”

“Like what?” C.W. asked.

“I don’t know, but I hope the answer’s over at the tower your guys found. Jim, can you hear me up there?”

“We’ve been monitoring your comms,” McKenzie said from the
Surveyor
.

“We’re going to head over to the tower now. Haul in C.W. and we’ll meet him there.”

“Affirmative. Alan, make your heading two hundred sixty-five degrees. We’ll correct your course for the crosscurrent en route.”

“I hear you, Jim. Two hundred sixty-five.” The pilot lifted the sub away from the wreck of the
Smithback
and killed the lights. The darkness became impenetrable once again as they moved steadily away from the ghostly hulk.

Alan turned on a portable tape player to drown out the incessant buzz of the forward thrusters. An up-tempo jazz song filled the cramped cockpit. “I’ve dived on about twenty wrecks,” he said after a few minutes. “You see that kind of collapse on older ships. After corrosion eats through the steel, they implode. We found a World War One freighter once off the coast of France. She’d fallen apart like that. Nothing more than a sandwich of decks and rust. But I’ve never seen anything like what happened to the
Smithback
.”

“I can’t explain it either.”

“But you have an idea?”

“Maybe,” was all Mercer said. Without at least a bit of evidence he wasn’t about to voice his off-the-wall theory.

Jervis flew the little sub by her sophisticated suite of sensors and didn’t seem bothered that he couldn’t see more than a half inch outside the Lexan dome. Mercer had become comfortable in the disorienting environment and settled deeper into his seat. The temperature in the cabin was down to fifty-eight degrees and he was thankful for the sweatshirt. He kept his hands clamped between his legs and still they felt frozen. Part of his chill came from what he feared he’d find at the tower.

Forty-five minutes later, Jim McKenzie called a change in course and warned them they were a thousand yards from the tower. The sonar showed the seafloor was three hundred feet below
Bob
’s rounded hull. Jervis nosed the little sub downward as they approached the mysterious structure.

“We’ll start at the base,” he said, switching on the external lights. “C.W. can’t dive this deep, so we’re on our own for a while.”

“Okay.”

The first of the tower’s massive legs came into view when they were fifteen feet out. The steel column was at least forty feet in diameter. There didn’t appear to be any anchor mechanisms other than the structure’s massive weight driving it into the seafloor. Fifty feet up from the bottom, bolted girders extended off the leg and presumably attached to other columns. Angled cross members completed the skeletal design. It was like finding the Eiffel Tower in thirteen hundred feet of water.

They circled the tower as they rose, spiraling upward while keeping the sub scant feet from the structure. When they were two hundred feet from the bottom and still a hundred feet below where C.W. could help them investigate, they found the first propeller. The massive five-bladed affair was stationary, but each vane was wickedly curved for maximum efficiency if it began to rotate. In the wavery light it was difficult to tell what the forty-foot propeller was made of, but it appeared to be some sort of flexible material. The navy used malleable props on its quietest submarines to reduce cavitation noises.

“What do you make of that?” Jervis asked without expecting an answer.

Nestled within the labyrinth of structural steel behind the propeller was a large enclosed capsule at least twice the size of the submersible. Mindful of the thruster nacelles attached to
Bob
, Alan nosed the sub between some of the larger struts to get a closer look at the strange construction. An axle ran from the propeller into the rounded box. From its bottom, several large pipes dropped into the gloom. Mercer and Alan hadn’t noticed the pipes on their way up.

“It’s like a giant windmill,” Mercer said. “Notice how the blades face into the prevailing current. Water passing over the blades makes them turn.”

“To do what? Does it pump something out of the ground, like oil?”

“I don’t know. Back us out and let’s see what’s above us.”

They found three more of the large propeller and housing assemblies as they ascended. At seven hundred feet below the surface, C.W. waited for them in the bulbous ADS.

“How many of these things are below us?” he asked through the comm link.

“Four.”

“And there’s two more above us.”

“Did you find any kind of storage tanks?” Mercer inquired.

“Just the propellers and their support mechanisms. None of them are turning right now and I think they’re all linked by pipes. One thing I did notice is the water’s colder around the thinner of the pipes.” Thinner was a relative term. The network of plumbing that connected the machines had a minimum diameter of five feet.

“How much colder?”

“Five to seven degrees, according to the suit’s sensors.”

Mercer felt he was on the trail of that first scrap of evidence he needed. “Can we check temperatures at the base of the tower?” he asked Jervis.

“No problem. Remember,
Bob
’s designed for scientific exploration. I can get temperature, pressure and salinity readings every fifteen seconds.”

“C.W., stay here,” Mercer ordered, gripped by excitement. He was pretty sure he knew what they’d found. There was a measure of risk staying this close to the tower, but he felt justified. “We’re going to need you when we come up. I want to open up one of the propeller’s housings to see what’s inside.”

“I’ll work at it while you’re down,” C.W. said in his surfer drawl.

“No. Wait for us to come back.”

“Oh, sure, man,” he said, chastened by Mercer’s sharp tone.

Alan Jervis eased the sub away from the tower and sent the craft toward the bottom again. “What are you thinking?” he asked after they’d sunk through a thousand feet.

“Turbines can be used for three things,” Mercer said. “Pumping something up, injecting something down or generating electricity. There aren’t any transmission lines so this rig isn’t producing power. We didn’t find any reservoirs to hold something being pumped from the seafloor. That leaves us something being pumped down into the ground.”

“Makes sense, but wouldn’t there be reservoirs of whatever was being injected?”

“Not if it were seawater. Or if the system was a closed loop.”

“Which one do you think it is?”

“In a sense, both.”

“You gonna explain that?”

“Ever wonder how they keep hockey rinks frozen?”

Jervis chuckled. “I grew up in Arizona. Hockey wasn’t much of a priority.”

“The Coyotes play in Phoenix,” Mercer pointed out. “It’s done by pumping salty water — brine — through a system of tubes under the ice. Because of the salt, the brine remains liquid below thirty-two degrees. The supercold pipes keep the ice frozen and voilà, slap shots in the desert.”

“Hold on,” Jervis interrupted, “we’re coming up on the bottom. The water temperature’s dropping faster than it should. It’s down four degrees in just fifteen feet.”

The lattice of struts and supports near the tower’s base wouldn’t allow them to get close to the pipes coming down from the turbine housings. Instead Mercer had Jervis circle the structure in ever-widening loops. Revealed under the lights, the bottom appeared featureless. The silt had a green cast in the artificial glow, and the blizzard of drifting organic material made it impossible to see more than a few feet. Still, Alan maneuvered the sub like an expert, keeping her nose scant feet above the abyssal plain.

“What’s that?” he asked after a few moments. “A crater?”

“Not sure,” Mercer said, but he was.

It took several minutes to cross over the crater from rim to rim. The bottom-profiling sonar showed it was a hundred feet deep. Mercer did the figures in his head. The crater had a volume of almost half a million cubic feet. He asked the pilot to hover at the edge of the large pit.

“What are we looking for?”

“Just hold it steady.” Mercer took hold of the manipulator controls.

“Hey, you can’t do that!” Jervis protested as the arms unfolded from their stowed position.

Mercer flexed them out straight, testing how his movements on the joysticks affected the joints and grapplers. “I’ll pay for any damage.”

In seconds he had the system figured. Like the controls for C.W.’s diving suit,
Bob
’s manipulator arms felt familiar because of his years working with mining equipment. Mercer returned one of the arms to its default attitude and moved the other closer to the crater’s rim.

“What’s going on down there?” McKenzie called over the comm.

“I want a soil sample,” Mercer said.

He eased the grapple hand into the ooze, causing a small avalanche of mud to slide below the submersible. Although there was no feedback resistance on the joysticks, Mercer could tell the arm hit something solid. A silvery bubble burst from the mud, and in the cavity he’d excavated he could see a strange white mass.

“What is that?” Jervis asked.

“Ice.”

“What? That’s impossible.”

Mercer turned to look at the pilot. “And yet there it is. The rig is a giant heat pump.”

“What for? This thing doesn’t make any sense.”

“Hey, guys,” C.W. called from above, his voice metallic from the echo within his suit. “Something’s happening up here. The blades are starting to turn. Wow.”

“What is it?” Alan asked quickly.

“Current can’t be more than a knot or two, but this thing’s spinning like it’s in a freaking hurricane.”

It took Mercer a second too long to digest what C.W. had just said. He’d been looking at the tower one way, ignoring the implications of another point of view. As he realized his mistake, his eyes widened, and yet when he spoke his voice carried a steel edge. “C.W., secure yourself to something. Grab on to the tower. Jim, can you hear me up there?”

“I’m here, Mercer, what’s going on?”

“We’re sitting on top of a methane hydrate deposit. That’s what sank the
Smithback
. You guys have got to get out of there.”

“What are you talking about?”

“Methane hydrate. The last great source of fossil fuel on the planet. It’s a gas kept locked in ice by the temperature and pressure on the seafloor. It’s normally stable, but I think this tower’s designed to cause the hydrates to melt. The gas is about one hundred fifty times the volume of its solid state. If the deposit is big enough, that much methane is going to cause the ocean to bubble up like champagne. If it’s bad enough, it will reduce the water density and the
Surveyor
’s going to lose buoyancy. She’ll sink like a stone.”

“Is it erupting now?” McKenzie asked, understanding the danger.

“It’s going to.” Mercer’s first assumption about the tower being a heat pump had been correct. Only now he realized it wasn’t forcing cold brine into the soil to keep the hydrate stable, it was designed to draw it up in order to dissipate the chill in the warmer shallower water and trigger a gas burst.

The
Smithback
must have sailed through an eruption and struck an enormous chunk of hydrate ice that hadn’t dissolved on its journey to the surface. But that damage hadn’t caused her to sink. It was the change in water density. Ships stay afloat because they weigh less than the volume of water their hulls displace. In the case of the
Smithback
, the frothing mix of gas and water wasn’t dense enough or didn’t weigh enough to support the vessel’s mass. She began to weigh more than the water she displaced and lost buoyancy. At some critical point she would have dropped from the surface so suddenly that no one could have saved themselves. The
Smithback
would have careened toward the seafloor much faster than normal. The ship could have been doing fifty or more miles per hour when she hit bottom. No wonder there wasn’t much air escaping the hulk. It had blown from her when she impacted.