They made their way back to the paraglider, called the icebreaker and asked Ivanov to send in a party to collect the dead and to bring in electric torches. Austin suggested that his men be armed. Knowing the captain's interest, Austin said he was hopeful that Karla was still alive. The captain said Maria Arbatov had been treated and was doing well. They wished each other good luck and clicked off.

Minutes later, the paraglider took off from a low hill with all the grace of a drunken gooney bird. They gained altitude and wheeled high over the island. Austin had thoroughly examined the charts, but still he was surprised at the size of the island. There was a lot of territory to cover with an aircraft that moved with a cruising speed of twenty-six miles per hour.

Austin marked their takeoff point as a center, and then he flew in an expanding spiral that allowed for an overlapping search of a large area. They saw only the featureless permafrost. Austin was about to head back to the beach to rendezvous with the boat party when Zavala shouted in his ear.

Austin followed Zavala's pointing finger and saw a well-defined track leading up the side of the volcano. They flew toward the volcano and saw that the trail was not a natural feature but rather a series of switchbacks cut into the side of the mountain. Austin suspected that man had a hand in the track's creation.

"Looks like a road," Austin said.

"That's what I thought. Want to take a look?"

The question was unnecessary. Austin had already brought the paraglider around, and they were soaring toward the lip of the caldera.

30

The subterranean city was laid out in a grid pattern under the domed roof of an enormous cavern. The ancient metropolis was cut off from the sun and should have been in complete darkness, but it shimmered in a silvery green light that emanated from every building and street.

"What makes everything glow so brightly?" Schroeder asked as he limped along a street with Karla at his side.

"I studied light-emitting minerals as part of a geology course," Karla said. "Some minerals glow under the influence of ultraviolet rays. Other types emit light from radiation or chemical change. But if we're right, and this is an old volcano, maybe there's a thermoluminescent effect caused by heat."

"Could this be an old magma chamber?" Schroeder said.

"That's possible. I just don't know. But there's one thing that I'm absolutely sure of."

"What's that, my dear?"

She gazed with awe at the glimmering edifices that stretched off in every direction. "We are strangers in a strange land."

After leaving the mural tunnel that led to the city, they had walked under a huge corbel arch down a broad ramp to an open plaza with a step pyramid built of huge blocks at the center. The processional motif, including the domesticated woolly mammoths, was continued on the exterior levels of the pyramid, although the colors were less bright than in the access tunnel. Karla surmised that it was a temple or platform for priests or speakers to address people gathered in the plaza.

A paved boulevard about fifty feet wide led into the heart of the city. They had strolled along the thoroughfare like a couple of tourists bedazzled by the bright lights of Broadway. The buildings were much smaller than Manhattan's skyscrapers-three stories at the most-yet they were architectural wonders, considering their probable age.

The promenade was lined with pedestals. The statues they once supported lay in unrecognizable heaps of rubble, as if they had been pushed off their perches by vandals.

Schroeder rested his sore ankle, then he and Karla explored a couple of buildings, but they were as empty as if they had been swept clean with a big broom.

"How old do you think this place is?" Schroeder said as they plunged deeper into the city.

"Each time I try to date it, I become tangled in contradictions. The fact that the murals show humans and mammoths coexisting places them in the Pleistocene period. That was a time span that ran from 1.8 million to ten thousand years ago. Even if we go with the most recent date of ten thousand years, the high level of civilization here is astonishing. We've always assumed that mankind didn't evolve from its primitive state until much later. The Egyptians' civilization is only around five thousand years old."

"Who do you think built this wonderful city?" '

"Ancient Siberians. This island was connected to an arctic continental shelf that extended out from the mainland. I didn't see any pictures of boats, indicating that this was pretty much a landlocked society. From the looks of it, this was a rich city."

"Since it was such a flourishing society, why did it end?"

"Maybe it didn't end. Maybe it simply moved somewhere and became the basis of another society. There is evidence that Europeans as well as Asians populated North America."

As Schroeder mulled the implications of Karla's analysis, excited voices could be heard shouting from behind them in the direction of the city gate. He squinted back along the boulevard. Pinpoints of light were moving in the area around the plaza. The ivory hunters had also blundered into the city.

"We're sitting ducks out here in the open," Schroeder said. "We can lose them easily if we get off this lovely avenue."

He slipped into an alley that connected with a narrow side street. The buildings were smaller than on the main boulevard; none was taller than one story. They appeared to serve more of a residential function than the grander, more ceremonial structures lining the main drag.

As a former soldier, Schroeder had accurately sized up the defensive situation. The city was a huge maze of hundreds of streets. Even with the omnipresent halo of light that shimmered over the city, as long as they kept alert and on the move through the labyrinth their pursuers would never catch them. At the same time, Schroeder was aware that they could only run for so long. Eventually, they would run out of food and water. Or luck.

His goal was to get to the far side of the city. He had hopes, supported by the relatively good quality of the air, that there might be another way out. The people who built this subterranean metropolis seemed to have done so with logic and reason. Thus it would be logical and reasonable that they had more than one way to get in and out. They were more than halfway across the city when Karla cried out in alarm.

She dug her fingers into Schroeder's arm. He slipped the automatic rifle off his shoulder. "What is it?" He glanced around at the silent facades as if he expected to see the leering faces of the ivory hunters in the windows.

"Something ran down that alley."

Schroeder followed her pointing finger with his eyes. Although the buildings produced their own light, they were built close together, and the narrow spaces between them were in deep shadow.

"Something or someone?"

"I-I don't know." She laughed. "Maybe I've been underground too long."

Schroeder had always trusted his senses above his analytical skills. "Wait here," he said. He approached the alleyway with his finger tight on the trigger. He edged up to the alley, stuck his head around the corner and flicked the flashlight on. After a few seconds, he turned and came back. "Nothing," he said.

"Sorry. It must have been my imagination."

"Come," he said, and, to Karla's surprise, he headed toward the alley.

"Where are you going?"

"If there is something out there, it's better that we sneak up on it rather than the other way around."