Desan reached out and touched the corroded brown surface of the vase, discovering a single bright remnant of blue glaze along with the gray encrustations of long burial. "How long—how long does it take to reduce a thing to this?"

"It depends on the soil—on moisture, on acidity. This came from hereabouts." Gothon tenderly set it back on a shelf, walked on, frail, hunch-shouldered figure among the aisles of the past. "But very long, very long to obliterate so much—almost all the artifacts are gone. Metals oxidize; plastics rot; cloth goes very quickly; paper and wood last quite long in a desert climate, but they go, finally. Moisture dissolves the details of sculpture. Only the noble metals survive intact. Soil creep warps even stone; crushes metal. We find even the best pots in a matrix of pieces, a puzzle-toss. Fragile as they are, they outlast monuments, they last as long as the earth that holds them, drylands, wetlands, even beneath the sea—where no marine life exists to trouble them. That bottle and that pot are as venerable as that great dam. The makers wouldn't have thought that, would they?"

"But—" Desan's mind reeled at the remembrance of the great plain, the silt and the deep buried secrets.

"But?"

"You surely might miss important detail. A world to search. You might walk right over something and misinterpret everything."

"Oh, yes, it can happen. But findingthings where we expect them is an important clue, Lord Desan, a confirmation—one only has to suspect where to look. We locate our best hope first—a sunken, a raised place in those photographs we trouble the orbiters to take; but one gets a feelingabout the lay of the land—more than the mechanical probes, Lord Desan." Gothon's dark eyes crinkled in the passage of thoughts unguessed, and Desan stood lost in Gothon's unthinkable mentality. What did a mind doin such age? Wander? Could the great doctor lapse into mysticism? To report such a thing—would solve one difficulty. But to have that regrettable duty—

"It's a feeling for living creatures, Lord Desan. It's reaching out to the land and saying—if this were long ago, if I thought to build, if I thought to trade—where would I go? Where would my neighbors live?"

Desan coughed delicately, wishing to draw things back to hard fact. "And the robot probes, of course, do assist."

"Probes, Lord Desan, are heartless things. A robot can be very skilled, but a researchers directs it only at distance, blind to opportunities and the true sense of the land. But you were born to space. Perhaps it makes no sense."

"I take your word for it," Desan said earnestly. He felt the weight of the sky on his back. The leaden, awful sky, leprous and unhealthy cover between them, and the star and the single moon. Gothon remembered homeworld. Remembered homeworld. Had been renowned in her field even there. The old scientist claimed to come to such a landscape and locatethings by seeing things that robot eyes could not, by thinking thoughts those dusty skulls had held in fleshly matter—

—how long ago?

"We look for mounds," Gothon said, continuing in her brittle gait down the aisle, past the bowed heads and shy looks of staff and students at their meticulous tasks. The work of tiny electronic needles proceeded about them, the patient ticking away at encrustations to bring ancient surfaces to light. "They built massive structures. Great skyscrapers. Some of them must have lasted, oh, thousands of years intact; but when they went unstable, they fell, and their fall made rubble; and the wind came and the rivers shifted their courses around the ruin, and of course the weight of sediment piled up, wind-and water-driven. From that point, its own weight moved it and warped it and complicated our work." Gothon paused again beside a further table, where holo plates stood inactive. She waved her hand and a landscape showed itself, a serpentined row of masonry across a depression. "See the wall there. They didn't build it that way, all wavering back and forth and up and down. Gravity and soil movement deformed it. It was buried till we unearthed it. Otherwise, wind and rain alone would have destroyed it ages ago. As it will do, now, if time doesn't rebury it."

"And this great pile of stone—" Desan waved an arm, indicating the imagined direction of the great dam and realizing himself disoriented. "How old is it?"

"Old as the lake it made."

"But contemporaneous with the fall?"

"Yes. Do you know, that mass may be standing when the star dies. The few great dams; the pyramids we find here and there around the world—one only guesses at their age. They'll outlast any other surface feature except the mountains themselves."

"Without life."

"Oh, but there is."

"Declining."

"No, no. Not declining." The doctor waved her hand and a puddle appeared over the second holo plate, all green with weed waving feathery tendrils back and forth in the surge. "The moon still keeps this world from entropy. There's water, not as much as this dam saw— It's the weed, this little weed that gives one hope for this world. The little life, the things that fly and crawl—the lichens and the life on the flatlands."

"But nothing they knew."

"No. Life's evolved new answers here. Life's starting over."

"It certainly hasn't much to start with, has it?"

"Not very much. It's a question that interests Dr. Bothogi—whether the life making a start here has the time left, and whether the consumption curve doesn't add up to defeat— But life doesn't know that. We're very concerned about contamination. But we fear it's inevitable. And who knows, perhaps it will have added something beneficial." Dr. Gothon lit yet another holo with a wave of her hand. A streamlined six-legged creature scuttled energetically across a surface of dead moss, frantically waving antennae and making no apparent progress.

"The inheritors of the world." Despair chilled Desan's marrow.

"But each generation of these little creatures is an unqualified success. The last to perish perishes in profound tragedy, of course, but without consciousness of it. The awareness will have, oh, half a billion years to wait—then, maybe it will appear; if the star doesn't fail; it's already far advanced down the sequence." Another holo, the image of desert, of blowing sand, beside the holo of the surge of weed in a pool. "Life makes life. That weed you see is busy making life. It's taking in and converting and building a chain of support that will enable things to feed on it, while more of its kind grows. That's what life does. It's busy, all unintended, of course, but fortuitously building itself a way off the planet."

Desan cast her an uncomfortable look askance.

"Oh, indeed. Biomass. Petrochemicals. The storehouse of aeons of energy all waiting the use of Consciousness. And that consciousness, if it arrives, dominates the world because awareness is a way of making life more efficiently. But consciousness is a perilous thing, Lord Desan. Consciousness is a computer loose with its own perceptions and performing calculations on its own course, in the service of that little weed; billions of such computers all running and calculating faster and faster, adjusting themselves and their ecological environment, and what if there were the smallest, the most insignificant software error at the outset?"

"You don't believe such a thing. You don't reduce us to that." Desan's faith was shaken; this good woman had not gone unstable, this great intellect had had her faith shaken, that was what—the great and gentle doctor had, in her unthinkable age, acquired cynicism, and he fought back with his fifty-two meager years. "Surely, but surely this isn't the proof, doctor, this could have been a natural calamity."