Hence the phytomines.
The technology was old — older than the human Moon, older than spaceflight itself. The Vikings, marauders of Earth’s dark age, would mine their iron from “bog ore,” iron-rich stony nodules deposited near the surface of bogs by bacteria that had flourished there: miniature miners, not even visible to the Vikings, who burned their little corpses to make their nails and swords and pans and cauldrons.
And so it went, across this battered, parched little planet, a hierarchy of bacteria and plants and insects and animals and birds collecting gold and silver and nickel and copper and bronze, their evanescent bodies comprising a slow, merging trickle of scattered molecules stored in leaves and flesh and bones, all for the benefit of that future generation who must someday save the Moon.
Berge and Xenia, solemnly, took ritual scraps of mustard-plant leaf on their tongues, swallowed ceremonially. With her age-furred tongue she could barely taste the mustard’s sharpness. There were no drawn-back frost covers here because these poor mustard plants would not survive to the Sunset: They died within a lunar Day, from poisoning by the cyanide.
Berge met friends and melted into the crowds.
Xenia returned home alone, brooding.
She found that her family of seals had lumbered out of the ocean and onto the shore. These were constant visitors. During the warmth of Noon they would bask for hours, males and females and children draped over each other in casual abandon, so long that the patch of regolith they inhabited became sodden and stinking with their droppings. The seals, uniquely among the creatures from Earth, had not adapted in any apparent way to the lunar conditions. In the flimsy gravity they could surely perform somersaults with those flippers of theirs. But they chose not to; instead they basked, as their ancestors had on far-remote Arctic beaches.
Xenia didn’t know why this was so. Perhaps the seals were, simply, wiser than struggling, dreaming humans.
The long Afternoon sank into its mellow warmth. The low sunlight diffused, yellow-red, to the very top of the tall sky.
Earth was clearly visible, wrapped in yellow clouds — clouds of dust and bits of rock and vaporized ocean thrown up there by the great impact a hundred years back. The scientists used to say it would take centuries to disperse the clouds. Now, nobody so much as looked at Earth, as if, now that it could no longer succor its blue satellite, the planet had become unmentionable, its huge wounds somehow impolite. But Xenia could make out a dim cloud of green, swathing the Earth: It was an orbiting forest, Trees that had survived the collision, still drawing their sustenance from the curdled air with superconductor roots.
The comet impact had been relatively minor, on the cosmic scale of such events. But it had been sufficient to silence Earth; nobody on the Moon knew who, or what, had survived on its surface. Xenia wondered if even those Trees could survive the greater and more frequent impacts that many had predicted were the inevitable outcome of the conflict in the Oort cloud, as the Crackers threatened to break through the Gaijin cordon, as warring ETs hurled giant rogue objects into the system’s crowded heart, century after century.
Such musing failed to distract her from thoughts of Berge’s illness, which advanced without pity. She was touched when he chose to come stay with her, to “see it out,” as he put it.
Her fondness for Berge was not hard to understand. Her daughter had died in childbirth. This was not uncommon, as pelvises evolved in heavy Earth gravity struggled to release the great fragile skulls of Moon-born children — and Xenia’s genes, of course, came direct from Earth, from the deep past.
So she had rejoiced when Berge was born, sired by her son of a lunar native; at least her genes, she consoled herself, which had emanated from primeval oceans now lost in the sky, would travel on to the farthest future. But now, it seemed, she would lose even that consolation.
But she was not important, nor the future, nor her complex past. All that mattered was Berge, here in the present, and on him she lavished all her strength, her love.
Berge spent his dwindling energies in feverish activities. Still his obsession with Leonardo clung about him. He showed her pictures of impossible machines, far beyond the technology of Leonardo’s time: shafts and cogwheels for generating enormous heat, a diving apparatus, an “easy-moving wagon” capable of independent locomotion. The famous helicopter intrigued Berge particularly. He built many spiral-shaped models of bamboo and paper; they soared into the thick air, easily defying the Moon’s gravity, catching the reddening light.
She wasn’t sure if he knew he was dying.
In her gloomier hours — when she sat with her grandson as he struggled to sleep, or as she lay listening to the ominous, mysterious rumbles of her own failing body, cumulatively poisoned, racked by the strange distortions of lunar gravity — she wondered how much farther humans must descend.
The heavy molecules of the thick atmosphere were too fast-moving to be contained by the Moon’s gravity. The air would be thinned in a few thousand years: a long time, but not beyond comprehension. Long before then people would have to reconquer this world they had built, or they would die.
So they gathered metals, molecule by molecule.
And, besides that, they would need knowledge.
The Moon had become a world of patient monks, endlessly transcribing the great texts of the past, pounding the eroding wisdom of the millennia into the brains of the wretched young. It seemed essential to Xenia they did not lose their concentration as a people, their memory. But she feared it was impossible. Technologically they had already descended to the level of Neolithic farmers, and the young were broken by toil even as they learned.
She had lived long enough to realize that they were, fragment by fragment, losing what they once knew.
If she had one simple message to transmit to the future generations, one thing they should remember lest they descend into savagery, it would be this: People came from Earth. There: cosmology and the history of the species and the promise of the future, wrapped up in one baffling, enigmatic, heroic sentence. She repeated it to everyone she met. Perhaps those future thinkers would decode its meaning, and would understand what they must do.
Berge’s decline quickened as the Sun slid down the sky, the clockwork of the universe mirroring his condition with a clumsy, if mindless, irony. In the last hours, she sat with him, quietly reading and talking, responding to his near-adolescent philosophizing with her customary brusqueness, which she was careful not to modify in this last hour.
“But have you ever wondered why we are here and now?” He was whispering, the sickly gold of his face picked out by the dwindling Sun. “What are we, a few million, scattered in our towns and farms around the Moon? What do we compare to the billions who swarmed over Earth in the great years? Why do I find myself alive now rather than then? It is so unlikely…” He turned his great lunar head. “Do you ever feel you have been born out of your time, as if you are stranded in the wrong era, an unconscious time traveler?”
She would have confessed she often did, but he whispered on.
“Suppose a modern human — or someone of the great ages of Earth — was stranded in the sixteenth century, Leonardo’s time. Suppose he forgot everything of his culture, all its science and learning—”
“Why? How?”
“I don’t know… But if it were true — and if his unconscious mind retained the slightest trace of the learning he had discarded — wouldn’t he do exactly what Leonardo did? Study obsessively, try to fit awkward facts into the prevailing, unsatisfactory paradigms, grope for the deeper truths he had lost? Don’t you see? Leonardo behaved exactly as a stranded time traveler would.”