“Gabriel believes it’s a lunar calendar designation. A date, so to speak.”

“Hmm…those central symbols do look like the sickle shapes of a waning or waxing moon.” Karen shifted back. “But if it is a date, what does it mean? The date when the inscription was written or some historical notation?”

“I’d guess the latter,” Miyuki said. “Some ancient historical event being described.”

“Why do you think that?”

Miyuki remained silent.

Karen glanced at her friend. “What?”

Miyuki sighed. “Gabriel came to his calendar conclusion by cross-referencing with the starscape etched on the ceiling of the inner chamber.”

Karen recalled the quartz star map on the room’s domed ceiling. “So?”

“He compared the chamber’s starscape with an astronomical program, then tied it to the lunar calendar.” Miyuki looked at Karen. “He’s calculated the rough date noted in the inscription.”

“Amazing…When? What’s the date?”

“Gabriel?”

The program answered: “The icons denote the fourth month of a lunar year.”

Karen noted the four moon sickles. “Early spring.”

“Correct…and from the relative position of the depicted constellations, I can extrapolate the approximate year.”

“Within a statistical error of fifty years,” Miyuki elaborated.

“Of course, I could not be more precise.”

“That’s close enough!” Karen’s mind spun. If Gabriel’s calculations were correct, this might be a clue to when the ancient ruins had been constructed. “What year? How long ago?”

“According to the astronomical map — twelve thousand years ago.”

Aboard the Nautilus submersible, Jack drifted over the debris field. From his position several yards away, he watched the tail fin of the Boeing 747 rise from the silt, drawn up by two four-inch-thick steel cables. Disturbed clouds of silt wafted up as the fin was pulled like a bad tooth from where it was embedded. Six hundred meters overhead, the motorized winch aboard the USS Gibraltar hauled on the cables, slowly but efficiently drawing its catch to the surface.

“Going for the next fish,” Jack called into his throat microphone. He worked the foot pedals and swung his sub around. He checked the Nautilus’s clock. He had been working for almost three hours, targeting the specific pieces of the plane the NTSB had picked out from the video feed of his first dive.

By now the salvage of Air Force One was becoming almost routine. Over the past three days they had hauled up almost forty sections of the plane. The recovered wreckage was now spread and numbered in the lower hangar deck of the USS Gibraltar like a macabre jigsaw puzzle.

Though the recovery of the plane was well under way, so far only four bodies had been recovered: two floaters discovered in the tricky currents, identified as two men from the press pool, and the pilot and copilot, found strapped to their seats. Jack drove away that memory. The plane’s crumpled nose cone had been one of the first pieces to be hauled to the surface. He had diverted his eyes from the shattered window as he attached the cables, but had caught a brief look. The pressures at this depth had crushed their bodies to a pulp. They looked like flesh-colored clay molded into a vague approximation of the human form. The only way to identify them were by their uniforms and their seats in the cockpit.

Since then, as Jack sifted through the wreckage, he had held his breath, fearing what else he might chance upon, but no other bodies were found. The impact and currents had thoroughly scattered the plane’s human cargo.

“We’re ready with the second winch,” the NTSB radioman announced.

“Aye. Ready on the second winch. Going for the next target.”

Jack swung the sub around and edged to the opposite side of the debris field. Ahead, another cable appeared, seeming to hang on its own, its end disappearing into the gloom above. It connected to a second surface winch aboard the Gibraltar. Jack dove the Nautilus down to the electromagnet hook attached to its end.

Working the sub’s external manipulator arms, he grabbed the hook and dragged it to one of the plane’s engine sections. Then he lowered the cable’s end and placed it against the metal nacelle.

“Okay,” he called up. “Energize!”

On his signal, he watched the cable’s electromagnetic terminal flip and attach to the engine’s side.

“Fish is hooked. Haul away!”

Jack backed his sub with a whine of thrusters. He watched the slack in the cable tighten; then the engine cowling slid from the silt.

Jack swung around. The graveyard was now almost half cleared. Only smaller pieces and sections of fuselage and wing remained. Under his sub, he passed over a large chunk of landing gear, its tires collapsed under the pressure. Another day or two and nothing would be down here.

As he spun the sub in a slow circle he noted movement off to his left. A school of hatchet fish flashed past the bubble of his submersible. He had been noting more and more denizens of the deep attracted to the light and noise of the salvage operation: long pinkish eels, scuttling crabs, and one six-foot-long dogfish. Off to the left, he watched a vampire squid shoot out of a crumpled nest of debris and snatch a passing hatchet fish. In a flick of tentacles, it vanished away.

These were his only companions. Swiveling his sub’s twin lamps, Jack observed the tall, flat-topped seamounts towering just at the edge of his light’s reach, giants looming over the wreckage. Closer, a forest of twisted lava pillars enclosed the space. From his sub’s hydrophones, the subsonic whistles and high-pitched clicks of the living sea called to him, a lonely sound.

As he waited, a twinge of isolation struck him. Down at these sunless depths, it was as if he had traveled to another world.

Sighing, Jack swung back around. He had a duty to perform and could not be distracted with stray thoughts. In another twenty minutes the pair of winch cables would drape back down once again, awaiting his help to snatch more wreckage. Until then, he turned his attention back to his own investigation.

He edged his sub toward the center of the debris field. Out of the silty gloom the crystal pillar appeared, glowing with the warmth of his reflected xenon lamps. The clear crystal shone with veins of azure and rose hues. Over the past days, he had recorded the spire from every possible angle, again saving it all to a secret DVD disk for review by his team. By now George had compiled a complete copy of the strange etchings on the crystalline surface.

Jack brought his sub near the pillar. Since the first exploratory dive, he had experienced no further radio interference or difficulties with his sub. The strange emanations had never returned. Jack was almost ready to admit that the odd sensation may have been due to something mundane, like a glitch in the Nautilus’s systems.

Hovering before the pillar, he reached out with his manipulator arm. Charlie had been hammering at him to try and clip a sample of the crystal. Jack reached with his titanium pincer and touched the pillar. From his hydrophones he heard a slight tinkle as metal struck crystal.

As the sound struck his ear, Jack felt every hair stand on end, as if his body had become a living tuning fork. His skin tingled, his sight wavered, and the world began to spin. He felt as if he were going to pass out. He suddenly could not tell which way was up. It was as if he were weightless, in space again. His ears rang, and distantly he heard voices calling to him, as if down a long tunnel — garbled, in some strange language.

Gasping, he slammed his foot hard on the right pedal, driving his submersible away from the crystal. As he broke contact, Jack snapped back into his own seat, back into his own body. The tingling sensation vanished.