"Two minutes," the technician at the control panel said. "We've got good pressure."

Beside him, Hui stirred. "I've been wondering about something," she said.

"Shoot."

"Remember when you explained about Ocotillo Mountain? You said that there were two kinds of countermeasures to prevent anyone, intentionally or unintentionally, from intruding into the vaults full of old nuclear weapons-passive security measures and active ones."

"That's right."

"I can understand what the passive measures would be-warning signs, images etched on metal, things of that sort. But what would the active countermeasures be?"

"I don't know. There was little talk about them at the conference, other than to note their existence. I gathered that information about them was classified." He turned toward her. "Why do you ask?"

"Those sentinels we found-those are passive measures in their own way, like you said. They simply beam out warnings. I guess I was wondering if they have active countermeasures, as well."

"I don't know," Crane replied slowly. "That's a very good question."

"One minute," the tech murmured.

And in the silence that followed, Crane could now hear distinctly-filtering up from the hatchway beneath his feet-the sharp, steady cadence of automatic weapon fire.

60

The tunnel-boring machine and the Doodlebug had been secured in the lateral retaining tunnel. The stabilization arm had been deployed, locking Marble Three into position directly above the anomaly. These final steps had been simulated many times; the actual procedures had been executed flawlessly. From here on, they were proceeding like surgeons, using only compressed air and the robotic arms. It had gone deathly silent inside the Marble.

"Give it another shot," Korolis whispered. "Gently. Gently."

"Aye, sir," Rafferty whispered back.

The three men communicated by looks and brief murmurs. Even Dr. Flyte seemed caught up in the moment. Again Korolis wiped the sheen of sweat from his face, then pressed his eyes to the tiny view port. A kind of awed reverence hung in the air, as if they were archaeologists excavating some supremely holy tomb. His pounding headache and the strange, metallic film that coated his tongue had vanished completely.

As he watched, Rafferty sent another puff of compressed air over the bottom of the hole. A small storm of sediment and loose gabbro erupted into the yellow glow of the Marble's exterior light, to be quickly sucked away by the vacuum unit.

"Careful," Korolis murmured. "What's the distance?"

"We're there, sir," Rafferty replied.

Korolis turned back to the viewscreen. "Another jet," he said.

"Another jet, aye."

He watched as another stream of compressed air shot over the bottom of the dig interface. He could see the two large sentinels floating on either side, glittering tails moving restlessly back and forth, tendrils drifting lazily. They were like spectators at a show. And why not? It was only right they should be here. They had come not only to witness his triumph, but also to guide him through the fabulous technological riches that awaited. It was not chance that brought him here on this most critical of dives: it was destiny.

"Again," he whispered.

Another jet of air; another gray storm of matter. The viewscreen quickly cleared as the vacuum unit sucked away the particulate. Korolis gripped the control handles even more tightly.

The radio on his control panel squawked into life. "Marble Three, this is Dive Control. Marble Three, this is Dive Control. Please acknowledge-"

Without taking his eyes from the viewscreen, Korolis reached down and snapped off the radio. He could see something now-a bright sheen, almost like the reflected gleam of metal.

"One more shot," he said. "Very carefully, Dr. Rafferty. Smooth as glass."

"Very good, sir."

A ripple of compressed air shot through the dark water beneath them; a fresh confusion of gray and brown particles. And then, as it cleared, Korolis gasped.

"My God," he breathed.

The air-jetting system had cleared the base of the shaft, revealing a smooth, glassy surface. To Korolis, pressed up against the eyepiece, it looked almost like someone blowing dust from a tabletop. Beyond lay an illusion-at least, he thought it was an illusion-of nearly infinite depth: a black infinity extending below. His searchlight was reflecting from the glassy surface, but he thought he could make out another light source, dim and strange, beyond and below the bright corona.

On either side of the Marble, the large sentinels had grown agitated. No longer content to simply drift, they were moving back and forth across the narrow diameter of the tunnel.

"Extinguish the light," Korolis said.

"Sir?" Rafferty said.

"Extinguish the light, please."

Now Korolis could see more clearly.

They were suspended above a massive cavity, of which only the smallest speck had been exposed. Whether the cavity was hollow-or whether the glassy surface directly below them filled it, like glue forced into a hole-he could not be sure. The velvety blackness gave no distinct impression, save that of vast depth.

But no…a faint light appeared from far below. As he stared, barely able to breathe, it slowly brightened.

It was coming closer.

"Sir!" said Rafferty, his normally reserved voice tense.

Korolis glanced at him. "What is it?"

"They've stopped broadcasting their signals."

"You've regained full control?" Korolis asked.

"Yes, sir. Wireless and remote systems, as well. Sensors, too: ultrasound, radiation, magnetometer, everything."

Korolis turned back to the viewscreen. "They're showing themselves to us," he murmured.

The light was closer now. Korolis noticed that it was wavering slightly: not in the lazy, undulant way of the sentinels' silhouettes, but in a sharp, almost fierce pulsation. And it was a color he had never seen before: a kind of deep metallic sheen, like the glow of black light on a knife blade. It seemed he could taste it as much as see it. This was a strangely unsettling sensation. Something about it made the hairs on the nape of his neck stand up.

"Sir!" said Rafferty again. "I'm picking up radiation signatures from below."

"What kind of radiation, Dr. Rafferty?"

"Every kind, sir. Infrared, ultraviolet, gamma, radio. The sensors are going crazy. It's a spectrum I don't recognize."

"Analyze it, then."

"Very well, sir." The engineer turned to his station and began punching in data.

Korolis turned back to the viewscreen. The glowing object was still rising toward them out of the rich blackness. Its strange color deepened. It was shaped like a torus, its outline pulsating ever more brilliantly. As he stared, openmouthed, the lambent otherworldliness of it brought back a sudden memory of childhood, long forgotten. When he was eight, his parents had taken him to Italy, and they had attended a papal mass at St. Peter's basilica. When the pontiff had brought out the host and raised it toward the congregation, Korolis felt himself galvanized by something like an electric shock. Somehow, the richness of the baroque spectacle brought the true import of it home to his young consciousness for the first time. There, at the tabernacle, the pontiff was offering them the most wonderful gift in the universe: the sacred mystery of the consecrated host.

Of course, organized religion had long since lost its usefulness for Korolis. But, staring at the wondrous, shimmering thing, he felt the same blend of emotions. He was among the chosen. And here was the offering of a higher power, the most wondrous of gifts.

His mouth was dry, and the coppery taste had returned. "Either one of you want to take a look?" he asked huskily.