Riptide (21 page)

“Nulls?”

“
Nihil
importantes.
Letters that don’t stand for anything, but are tossed in to confuse the codebreaker.”

A boat horn sounded outside, deep and mysterious, and Hatch checked his watch. “It’s ten,” he said. “I’d better go. They’ll
be sealing the flood tunnels and draining the Water Pit in a few minutes. Good luck with Kerry.”

L
eaving Base Camp, Hatch began jogging up the path toward Orthanc, eager to see the new structure that had materialized over
the Water Pit in just forty-eight hours. Even before he reached the crest of the island, he could make out the glassed-in observation
tower, a narrow deck running around its outer edge. As he drew closer, he could see the massive supports that suspended the
derrick almost forty feet above the sandy ground. Winches and cables dangled from the underside of the tower, reaching down
into the darkness of the Pit.
My God,
Hatch thought.
They must be able to see this thing from the mainland.

With this, his thoughts drifted back to the lobster festival and to what Clay and his old teacher had said. He knew that Professor
Horn would keep his opinions to himself. Clay, though, was another matter. So far, public sentiment toward Thalassa seemed
overwhelmingly favorable; he’d have to be careful to keep it that way. Even before the festival had come to a close, he’d
spoken to Neidelman about giving Donny Truitt a job. The Captain had promptly added him to the excavation crew that would
start digging at the bottom of the Water Pit as soon as it was drained.

Hatch approached the derrick and climbed the external ladder. The view from the observation deck was magnificent. The ever-present
mist was breaking into tatters under the hot summer sun, and he could just make out the dark purple stripe of the mainland.
The sun glinted off the ocean, turning it the color of beaten metal, and the surf broke over the windward reefs, surrounding
them with spume and a line of drifting wrack. A phrase from Rupert Brooke surfaced unbidden in his mind:

The little dulling edge of foam

That browns and dwindles as the wave goes home.

He raised his head at the sound of voices. On the far side of the observation deck he could see Isobel Bonterre, her wetsuit
shining damply in the sun. She was leaning over the railing, twisting the excess water out of her hair and talking animatedly
to Neidelman.

As Hatch strolled over, she turned to him with a grin. “Well, well! The man who saved my life!”

“How’s your wound?” Hatch replied.

“De rien, monsieur le docteur.
I was out diving this morning at six, no doubt while you were still snoring the loud snores. And you will not believe what
I have discovered!”

Hatch glanced at Neidelman, who was nodding and puffing on his pipe, clearly pleased.

“That stone foundation I found on the seabed the other day?” she continued. “It runs along the inside wall of the reefs, all
around the southern end of the island. I traced the remains this morning. There is only one explanation for it: the foundation
to an ancient cofferdam.”

“An ancient cofferdam? Built around the end of the island? But why?” Even as Hatch asked the question, he realized the answer.
“Jesus,” he exhaled.

Bonterre grinned. “The pirates built a semicircular dam all along the southern reefs. They sunk wooden pilings, arcing out
from the shore into the shallow water, then coming back to land again, like a stockade fence in the sea. I found tracings
of pitch and oakum, which they probably used to make the pilings watertight. Then they pumped out the seawater, exposed the
sea floor around the beach, and excavated the five flood tunnels. When they were done, they simply destroyed the cofferdam
and let the water back in.
Et voilà,
the traps were set!”

“Yes,” Neidelman added. “Almost obvious, when you think of it. How else could they build underwater flood tunnels without
the benefit of scuba gear? Macallan was an engineer as well as an architect. He advised on the construction of Old Battersea
Bridge, so he knew about shallow-water construction. He undoubtedly planned all of this, down to the last detail.”

“A cofferdam around the entire end of the island?” Hatch said. “Sounds like a huge task.”

“Huge, yes. But remember, he had over a thousand enthusiastic laborers to do it. And they had enormous chain pumps from the
bilges of their ships.” There was another blast from a boat horn, and Neidelman checked his watch. “Fifteen minutes until
we blow the explosives and seal those five flood tunnels. The mist is clearing nicely; we should have a fine view. Come on
inside.”

The Captain ushered them inside Orthanc. Beneath the windows that lined the walls of the tower, Hatch could see banks of equipment
and horizontally mounted monitors. Magnusen and Rankin, the geologist, stood at stations in opposite corners of the tower,
while a couple of technicians Hatch didn’t recognize were busy wiring and testing components. Against one wall, a series of
screens showed closed-circuit video feeds from around the island: the Command Center, the mouth of the Pit, the interior of
Orthanc itself.

The most remarkable feature of the tower was a massive glass plate that occupied the center of the floor. Hatch stepped forward
and gazed down into the maw of the Water Pit.

“Watch this,” Neidelman said, flicking a switch on a nearby console.

A powerful mercury arc lamp snapped on, its beam stabbing down into the darkness. Below, the Pit was drowned in seawater.
Bits of seaweed floated in the water and brine shrimp, attracted by the light, jerked and played just below the surface. A
few feet into the murky water, he could make out stumps of old timbers, heavy with barnacles, their ragged lengths disappearing
into the depths. The fat, metal-jointed pump hose ran along the ground and over the side of the Pit, joining half a dozen
other, narrower cables and feeder lines.

“The throat of the beast,” Neidelman said with grim satisfaction. He swept his hand over the consoles ranged beneath the windows.
“We’ve equipped the tower with the latest remote-sensing equipment, including L-band and X-band synthetic-aperture downward-pointing
radar. All with dedicated links to the Base Camp computer.”

He checked his watch again. “Dr. Magnusen, is the comm station in order?”

“Yes, Captain,” the engineer said, brushing her short hair back. “All five marker buoys are transmitting clearly, ready for
your arming signal.”

“Is Wopner in Island One?”

“I beeped him about five minutes ago. He should be there shortly, if he isn’t already.”

Neidelman strode toward a bank of controls and snapped the radio to life.
“Naiad
and
Grampus,
this is Orthanc. Do you read?”

The boats acknowledged.

“Take your stations. We blow the charges in ten minutes.”

Hatch moved to the window. The mist had retreated to a distant haze, and he could see the two launches power away from the
pier and take up positions offshore. Ringing the inside of the reef, along the southern end of the island, he could make out
the five electronic buoys that marked the flood tunnel exits. Each flood tunnel, he knew, had now been mined with several
pounds of Semtex. The buoy antennas winked in the light, ready to receive the detonation signals.

“Island One, report,” Neidelman spoke into the radio.

“Wopner here.”

“Are the monitoring systems on-line?”

“Yes, everything’s hunky-dory.” Wopner sounded dejected.

“Good. Advise me of any changes.”

“Captain, why am I here?” the voice complained. “The tower’s fully networked, and you’re gonna be running the pumps manually.
Anything you need to do, you can do there. I should be working on that damn code.”

“I don’t want any more surprises,” Neidelman replied. “We’ll set off the charges, seal the flood tunnels, then pump the water
out of the Pit. You should be curled up with that journal again in no time.”

There was a flurry of activity below, and Hatch could see Streeter directing a team into position around the pump hose. Bonterre
came back in from the deck, her hair streaming behind her. “How long until the fireworks start?” she asked.

“Five minutes,” said Neidelman.

“How exciting! I love a big explosion.” She looked at Hatch with a wink.

“Dr. Magnusen,” Neidelman said. “A final check, if you please.”

“Certainly, Captain.” There was a brief silence. “Everything’s green. Comm signals are good. Pumps primed and idling.”

Rankin gestured Hatch over and pointed toward a screen. “Check it out.”

The screen showed a cross section of the Pit, marked in ten-foot intervals down to one hundred feet. A blue column sat inside
the cross section, level with the surface.

“We were able to snake a miniature depth meter into the Pit,” he said excitedly. “Streeter sent a dive team down earlier,
but they couldn’t get farther than thirty feet because of all the debris clogging the works. You wouldn’t believe how much
junk has collected down there.” He nodded at the screen. “With this, we’ll be able to monitor the water level drop from here.”

“All stations, listen up,” Neidelman said. “We’ll blow in series.”

A silence fell in the observation tower.

“Arming one through five,” Magnusen said quietly, her stubby fingers moving across a console.

“Ten seconds,” Neidelman murmured. The atmosphere deepened.

“Fire one.”

Hatch looked seaward. For a pregnant moment, all seemed still. Then an enormous geyser ripped out of the ocean, shot from
within by orange light. A second later, the shock wave shivered the windows of the observation deck. The sound rumbled across
the water, and thirty seconds later a faint answering rumble echoed back from the mainland. The geyser ascended in a strange
kind of slow motion, followed by a haze of pulverized rock, mud, and seaweed. As it began falling back in a dirty plume, steep-walled
waves spread out across the ocean, beating against the chop.
Naiad,
the nearer of the two boats, rocked crazily in the sudden swell.

“Fire two,” Neidelman said, and a second explosion ripped the underwater reef a hundred yards from the first. One by one,
he detonated the underwater explosives, until it seemed to Hatch that the entire southern coast of Ragged Island had been
caught in a lashing waterstorm.
Too bad it’s not Sunday,
he thought.
We’d have done Clay a favor, waking all those people asleep at his sermon.

There was a brief pause while the water settled and dive teams examined the results. After receiving word that all five tunnel
entrances were sealed, Neidelman turned to Magnusen. “Set the outflow valves on the pumps,” he said. “Maintain a 20,000 GPM
rate of flow out of the pit. Streeter, have your team stand by.”

Radio in hand, he turned toward the group assembled in the tower.

“Let’s drain the Water Pit,” he said.

There was a roar on the southern shore as the pump engines came to life. Almost simultaneously, Hatch heard a great, reluctant
throbbing from the Pit as water was sucked up from its depths. Looking down, he could see the thick hose stiffening as the
water began its journey out of the Pit, across the island, and back to the ocean. Rankin and Bonterre were glued to the depth
display, while Magnusen was monitoring the pump subsystem. The tower began to vibrate slightly.

A few minutes passed.

“Water level down five feet,” Magnusen said.

Neidelman leaned toward Hatch. “Tidal displacement here is eight feet,” he said. “Water never drops lower than eight feet
in the Pit, even at the lowest low tide. Once we reach ten feet, we’ll know we’ve won.”

There was an endless, tense moment. Then Magnusen lifted her face from a dial.

“Water level down ten feet,” she said matter-of-factly.

The team looked at each other. Then, suddenly, Neidelman broke into a broad grin.

In an instant, Orthanc’s observation tower became a place of happy bedlam. Bonterre whistled loudly and jumped into the arms
of a surprised Rankin. The technicians slapped each other’s backs enthusiastically. Even Magnusen’s lips twisted into what
might have been a smile before she returned her gaze to the monitor. Amid the clapping and cheering, someone produced a bottle
of Veuve Cliquot and some plastic champagne glasses.

“We did it, by God,” Neidelman said, shaking hands around the room. “We’re draining the Water Pit!” He reached for the champagne,
tore off the foil, and popped the cork.

“This place got its name for a reason,” he said, pouring glasses. Hatch thought he could detect an emotional tremor in the
Captain’s voice. “For two hundred years, the enemy has been the water. Until the Water Pit could be drained, there could be
no recovery of the treasure. But my friends, as of tomorrow, this place will need a different name. My thanks and congratulations
to you all.” He raised his glass. Faint cheers resounded across the island.

“Water level down fifteen feet,” Magnusen said.

Holding his champagne in one hand, Hatch walked toward the center of the room and looked down into the glass. It was unsettling,
looking into the mouth of the Pit. Streeter’s team was standing beside the enormous hose, monitoring the flow. As the water
was pumped out at a rate of 20,000 GPM—one swimming pool’s worth of water every two minutes—Hatch thought he could actually
see the surface level dropping. It crept down the seaweed-covered beams, exposing, millimeter by millimeter, the barnacle-
and kelp-encrusted walls. Perversely, he found himself struggling with a strange feeling of regret. It seemed anticlimactic,
almost unfair, that they should accomplish in less than two weeks what two hundred years of pain, suffering, and death had
been unable to achieve.