When he had secured the map with small magnetic disks, Renzi glanced up to gaze at the expectant faces englobing him. In addition to Larson Sands, Kimber Crawford, and Halley Trevanon, the onlookers included every expedition scientist and Captain McCarver.

"Well, friends, we've made it," the small scientist said. "Now comes the hard part. We will launch a scouting expedition at the beginning of first watch tomorrow. Those taking part will be myself, Professor Linder, Mr. Sands, and Spacer Forbes."

A quiet buzz of conversation suddenly filled the compartment. Competition for the first landing had been keen. Renzi had advised Sands of his selection only an hour earlier, and had warned him to be prepared for some objections. He did not have long to wait.

"Why Sands?" Professor Taren LeBlanc demanded. LeBlanc was the youngest of the expedition's scientists, and a man who did not trouble himself overly with the feelings of others.

"Mr. Sands will be in charge of site security. He is an accomplished marksman and has military experience. Except for Miss Trevanon, that makes him unique among us."

"Security? What in hell do we need security for? The damned planet's been dead for two centuries!"

"There are six other expeditions in orbit about Earth," Renzi replied. "Captain McCarver received calls from most of them as soon as we took up orbit. They are naturally curious as to what we are about."

"He hasn't told them has he?"

McCarver,Vixen 's captain, was an oversize man who looked out of place in the crowded compartment."I kept my explanation general, Professor LeBlanc. However, I managed to leave the impression that we are merely stopping here preparatory to going on to Luna."

Professor Renzi nodded. "That will be our cover story. We are historians here to research the lives of our Lunar ancestors. We are stopping at Earth to retrieve some records pertaining to the earliest lunar colonies. We do not know why these other expeditions are here. Some of them may be after the same data we are. For that reason, we will establish strict rules concerning what may be said during ground to orbit communications and will establish a sensor perimeter around the laboratory site."

"Damned silliness if you ask me," LeBlanc grumped. Nor was he alone in his attitude.

"Perhaps so," Sands replied, "but the factor wants it that way."

Renzi glanced up at the surrounding faces. "If that matter is cleared up, let us get on with the briefing. I direct your attention to the map. The Borman expedition found the energy screen laboratory here at the base of the Sierra Nevada Mountains in what was once California. We will scout the site from the air and pick a safe landing area. From there, we will determine the amount of effort required to seal the old laboratory and environmentally condition it. If we find conditions to our liking, we will send the landing boat back to begin ferrying the rest of you down."

"How do we know the Bormans didn't take the data we are looking for?" someone asked. The subject had been a major topic of debate on the trip from Titan.

"The one record we have speaks of experiment summary reports. The Bormans did not, as far as we know, find any detailed data on screen construction or principles of operation. Since energy screens were not the reason they came to Earth, we can assume they did not spend a great deal of time looking.

Now then, if there is nothing else, let's make all preparations for first landing!"

Chapter 23: Earth.

Larson Sands sat in the cramped seat and gazed at the limb of the planet through the landing boat's windscreen. They were high above the night hemisphere, racing toward the sunrise terminator. The atmosphere was an absurdly thin line of color backlit by the spotted sun -- a band of orange, red and yellow outlining the obsidian sphere of the planet. The sight fascinated Lars. Thousands of generations had lived beneath that impossibly thin envelope of air, never understanding the fragility of their existence.

Like the other three men in the cramped passenger compartment, Lars was encased in a bulky New Hollander environment suit. The air he breathed was cool enough, but saturated with the odor of plasticizers and other organic compounds. The smell was making him queasy. There was also an annoying squeak in his recirculation fan, something he had missed when he had worn the suit during the factory acceptance test. He wondered how many other problems he had let by and who would die because of them. The thought was a chilling one, more frightening even than the prospect of battle.

A tiny tug at his body signaled the landing boat's arrival at the outer limit of Earth's atmosphere. After several long minutes, a high-pitched keening filled the cabin. The sound was at the very limits of audibility, a noise more felt than heard. It set Lars's teeth on edge.

The landing boat began to lurch from turbulence, a harbinger of what it was like to fly through the roiled daytime skies of Earth. At a distance of only 150 million kilometers, the sun had the power to boil oceans and set up vast convection cells. Only one raised in Saturn's atmosphere could appreciate how violentsuch phenomena could get.

Twenty minutes after entering atmosphere, the landing boat passed from night into day. The rocking and shaking grew more violent, as though the shafts of sunlight were a tangible barrier to be cleaved. The faceplate on Sands's suit darkened automatically as he found himself staring directly into the sun. Then the landing boat dipped into cloud, leaving him momentarily blinded until his suit's polarizing circuits had time to react.

The clouds were gray, just like the uppermost layer of ammonia clouds on Saturn. There was no hint that they were boiling hot. Sands remarked on that fact over the intercom.

"They aren't," Renzi's voice replied. "In fact, these clouds are composed of ice crystals. The real heat occurs much lower in the atmosphere."

"We should be out of the clouds in another few minutes," the pilot announced.

There was a general stirring as each of the landing boat's passengers shifted in their seats for the best possible view. Lars found himself straining to look down the tunnel formed by Forbes's and Renzi's helmets and past the obstruction of the windscreen's centerline brace. For long minutes, he could see nothing but white. Then, with only a moment's warning, the clouds parted to reveal the bare Earth stretched out below them.

Four gasps echoed in unison over the intercom. The air was filled with haze. The panoramic view was softened into invisibility in the middle distance, leaving the landing boat inside a bubble of scenery that was dominated by the white covered hillocks and slope sided canyons far below. Sands had seen pictures of snowscapes and thought for a moment this must be one. Then he realized what this vast, white plain had once been the floor of an ocean. The covering was the salt that had been left behind when all the water boiled away.

"Where are we?" Renzi asked. There was a tinge of reverence in his words.

"About two hundred kilometers from the ancient coastline," Professor Linder, their navigator, replied.

"This was all deep water once."

A quick glance at the cockpit displays told Sands they were ten kilometers up and descending slowly.

Distance and haze made it difficult to make out anything but the largest details. Even so, the view was daunting. He wondered if they would find the ocean floor littered with the wreckage of ships when they dropped lower.

The plain of bleached ground marched steadily astern as their engines pushed them forward. Then the white wasteland came to an abrupt end, to be replaced by a different desolation. It was as though some giant had run low on white paint and had substituted brown instead. This, Sands realized, must have been the western shore of North America.

"Let's fly south," Renzi ordered as they flew over a line of ragged bluffs. "I want to see Los Angeles."

The landing boat made a sharp turn and followed the coast. Since Sands was on the right side, he had to content himself with viewing the desiccated seabed. After fifteen minutes of level flight, he was alerted by the oaths of the others.

All of them had seen photographs, of course. Earth's cities were largely destroyed. When the oceans had boiled, the reduction in weight on the crust had redistributed all manner of stresses. The result had been a series of continent shattering earthquakes. Most manmade structures had collapsed. Much of the rubblehad then been eaten away, scoured by superheated hurricanes and corroded by the effects of steam and oxygen. The constant winds had stirred up the cubic kilometers of salt and chalk to the west and dumped much of it onto the city's corpse. One could still make out a few manmade details beneath the shroud of white. Scattered straight lines showed where city streets had been. Here and there, the skeletal remains of a particularly stout skyscraper thrust rust red girders toward the clouds.

They orbited for fifteen minutes, allowing each of them to see what the flaring sun had done to one of the planet's great cities. Then Renzi gave the order to turn back northeast. As the boat flew on, a mountain range came into view. Forbes banked to the left and began to fly parallel to it. Every few minutes, Linder would call out the name of some long dead city as a position check.

As they droned northward, Sands gazed out at the brown and gray land beyond the mountains. Here the landscape had been sundered by a range of volcanoes that followed some ancient fault. Some still smoked on the horizon.

Professor Linder's comments became more frequent as he directed Forbes to change his course slightly and to slow down. The land below them was no different from what they had been traversing for nearly half an hour. Still, it was possible to hear Linder's excitement as he directed them toward their goal.

Finally, he looked up from his navigation display and pointed toward a nondescript landscape of rolling hills.

"Land at the base of that big one on the right. The laboratory's somewhere near there."

"Acknowledged," came the pilot's terse reply.

The landing boat slowed to a hover just as though it were preparing to go aboard a cloud city. Instead, they dropped toward the ground, kicking up clouds of dust with the underjets. The ground was obscured for the last few seconds before Sands felt the satisfying bump that signaled their arrival. There was a moment of silence while Forbes shut down the reactors. Then Professor Renzi ordered the canopy raised.

One by one, the members of Titan's first expedition to Earth clambered awkwardly to their feet. They stepped over the raised coaming of the flight cabin and strode clumsily across the boat's wing to where a ladder let them down. Then they worked their way slowly down the rungs until they stepped off onto the powdery soil.

"Why the hell didn't they leave a beacon?"

Sands glanced up at the muttered complaint. He did not answer right away. He was too out of breath.

For the past six hours, they had searched in vain for some sign of the underground laboratory. So far, they had found nothing. Out of frustration, he and Arthur Linder had climbed a small hill for a panoramic view of the search area. The hill had proven taller than expected, and by the time they reached the top, every breath was like inhaling live flame. Beads of sweat poured down Sands's face and into his eyes, obscuring his vision. Even their cooling systems were laboring against the steam bath atmosphere. The radiators on Linder's suit -- and he suspected his own -- were glowing a dull red after their climb.

"What good would it have done?" he asked finally when he had regained some control over his breathing. "Anything they left would be corroded into uselessness by now. Besides, I don't think they planned to come back."

The geologist's sigh was like a hurricane in Sands's earphones. "I know. Still, it would have made findingthis place a damned sight easier if they'd just stuck a flag up or something."

"Amen to that!"

The record of the Borman expedition had given precise coordinates for the location of the energy screen laboratory. Precise, that is, until one realized just how big a planet truly is. They had been crisscrossing the landscape for some sign the other expedition had been there. They had found nothing but bare rock and blowing dust. Even the remains of vegetation, if indeed there had ever been any in the vicinity, had been uprooted by the steady wind that scoured the landscape.

"See anything?" Linder asked.

Sands shook his head, and then remembered that the professor could not see the gesture inside his helmet. "Nothing. Maybe this isn't the place."

"These are the coordinates in the Borman record."

"Maybe they recorded the location wrong. It could have been a typo. Or maybe Kelt Dalishaar altered the coordinates for security reasons."

"I hope you're wrong. Let's sweep down the west side of the hill."

Sands turned awkwardly in the bulky suit. The few minutes they had rested had allowed his cooling unit to get rid of most of the heat of his exertions. Now the sweat on his face felt cold. Linder started down the hill at a right angle to the way they had come up. He moved cautiously, testing each step before putting his full weight down. Sands did the same. If either of them were to slip, they could easily damage a radiator. That would mean death by slow broiling.

"What's this?" Linder asked as he stopped halfway down the slope. He poked at something in the soft ground with his boot. The toe caught and dragged a long, black object to the surface. Sands leaned forward for a closer look, being careful not to overbalance. The long ribbon turned out to be an electrical cable, and not one of Earthly manufacture. The insulation was of a variety much favored by Saturnian cloud cities for its toughness and lightweight. It had not been invented until more than a century after the Earth had been abandoned.

"How much do you want to bet that this cable is from the Borman expedition?" Linder asked. He, too, had recognized the insulation.

"No bet. Where do you suppose it leads?"

"Only one way to find out." The scientist wrapped the cable around both gauntletted hands and pulled it taut. He stopped when he had exposed cable running five meters in both directions.

"Which way?" Sands asked.

"Pick one."

"Downhill!"

They took turns pulling the cable out of its shallow trench and following it down the side of the hill. For the most part, it came to the surface easily enough. On the few occasions when it hung up, Sands would carefully unearth more cable with a shovel further down the line. Then they would start over. In that way, they were able to traverse 300 meters in only fifteen minutes. It was like following some living thing as it burrowed through the ground. The black cable disappeared into the ground at the base of the hill and noamount of pulling would bring it into view.

"Shovel!" Linder ordered.

Sands unshipped the tool and began to dig in line with the trench they had already uncovered. After two minutes, he frowned. He was down nearly thirty centimeters and had found nothing.

"What do you think?"

The expansive shrug was evident even through the intervening barrier of Linder's suit. "Maybe it took a sharp turn," the scientist said. "Tell you what, let's dig down and see what has us hung up."

Sands dug again where the cable entered the ground. It soon became evident that the cable was headed deep. Sands followed it, taking care to ensure the sharp blade did not slice through the long black ribbon.

He dug continuously for five minutes, and then stopped when the blade struck something hard. The shock on his arms was sufficient to rattle his teeth.

"What's the matter?" Linder asked.

"I just hit something solid."

The scientist unclipped his own shovel and for several minutes they worked furiously to uncover the object buried in the ground. What they found was a round metal disk nearly a meter across set in a rocky material Sands recognized from photographs he had seen. The stuff was concrete.

"What is it?"

"Manhole cover," Linder diagnosed. "I think we're on to something."

"How do we get it up out of there?"

"I don't think we do. It looks to be rusted solid into its frame. We'll have to burn it."

"Is this part of the laboratory?"

"It probably leads to a utility tunnel feeding the laboratory. The Bormans spliced into the old distribution network to power the laboratory. They wouldn't have strung their cable any farther than necessary."

"Shall we keep digging?"

"No, that's enough," Linder replied. "Let's mark this spot with a flag and get back to the others. We'll need one of our small excavators down from orbit before we can go much farther."

"What if this isn't the laboratory?"

"Then we keep looking. Still, I am hopeful. Someone from Saturn passed this way."

"Just as long as I don't have to shovel any more dirt."

Linder's chuckle was a base rumble in Sands's earphones. "Before this is over, Lars, you will probably hold the Saturnian record for dirt shoveling!"

Sands groaned as he felt the ache that had already begun to suffuse his shoulders. That's what I'm afraid of."

Chapter 24: Laboratory.

Kimber Crawford sat in the cockpit of the landing boat and chewed her lower lip as the pallid hills and valleys of the ancient seabed crawled slowly astern. The sight stirred something deep within her, something she did not fully understand. Her first sight of Earth through the viewdome had left her speaking in hushed tones. It had been as though normal speech would have disturbed the rest of the billions of honored dead who remained on the once-green world.

Her reaction surprised her. Like most inhabitants of the Saturn system, she enjoyed view walls and the Earth dioramas of the cloud cities. Even so, nothing in her past hinted at the depth of feeling for a world she had never expected to visit. She wondered if there weren't something in the human makeup that instinctively yearned for 1.00 standard gees and a 24-hour day.

It had taken five such days to excavate the energy screen laboratory and to make it livable. During that time Kimber had chafed with impatience as the landing boat returned repeatedly to the ship, only to be loaded with vital equipment and sent Earthward without her. Her turn had finally come. She donned her environment suit, climbed into the seat next to Spacer Forbes, and waited patiently whileVixen 's crew filled every cubic centimeter of available space with supplies and equipment. When they finally cast off, Kimber had been packed into her seat like an emergency ration in a squeeze tube.