The Fourths at Bar Kea Desert Station encouraged the friendship. They had been disappointed by Esh's refractory silences and his outward display of dull-normal intelligence. He was studious but incurious. He sat wide-eyed in the classrooms the adults had designed for him, and he absorbed a reasonable amount of information, but he was indifferent to it all. The sky was full of stars and the desert was full of sand, but stars and sand might have traded places for all it mattered to Esh. Whether he spoke to the Hypotheticals, or they to him, no one could say. He was stubbornly silent on the subject.
Esh was at his liveliest when he was alone with Sulean. They were allowed to leave the station on certain days to explore the nearby desert. They were supervised, of course—an adult was always within sight—but compared to the closeted spaces of the Station this was wild freedom. Bar Kea was formidably dry, but the scarce spring rains sometimes pooled among the rocks, and Sulean delighted in the small creatures that swam in these short-lived ponds. There were tiny fish that encased themselves in hibematory cysts, like seeds, when the water dried, and sprang back to life during the rare rains. She liked to cup the populated water in her hands, Esh watching with silent wonder as the wriggling things slipped between her fingers.
Esh never asked questions, but Sulean pretended he did. At the Station she was always being taught, always being encouraged to listen; alone with Esh she became the teacher, he the rapt and silent audience. Often she would explain to him what she had learned that day or week.
People had not always lived on Mars, she told him one day as they wandered among sunlit, dusty rocks. Years and centuries ago their ancestors had come from Earth, a planet closer to the sun. You couldn't see Earth directly, because the Hypotheticals had enclosed it in a lightless barrier—but you knew it was there, because it had a moon that circled it.
She mentioned the Hypotheticals (called by Martians Ab-ashken, a word compounded of the root-words for "powerful" and "remote"), cautiously at first, wondering how Esh would react. She knew he was part Hypothetical himself and she didn't want to offend him. But the name provoked no special response, only his usual blank indifference. So Sulean was free to lecture, imagine, dream. Even then the Hypotheticals had fascinated her.
They live among the stars, as far as anyone knows, she told the boy.
Esh, of course, said nothing in return.
They're not exactly animals, they're more like machines, but they grow and reproduce themselves.
They do things for no apparent reason, she told him. They put the Earth inside a slow-time bubble millions of years ago, but no one knows why.
No one has talked to them, she said, unless you have, I suppose, and no one has seen them. But pieces of them fall out of the sky from time to time, and strange things happen…
Pieces of them fall from the sky: this last piece of information caused considerable consternation among Dr. Dvali's Fourths.
Dvali cleared his throat and said, "There's nothing about such an event in the Martian Archives."
"No," Sulean admitted. "Nor did we ever mention it in direct communication with the Earth. Even on Mars it's a rare occurrence—something that happens once every two or three hundred years."
Mrs. Rebka said, "Excuse me, but what happens? I don't understand."
"The Hypotheticals exist in a kind of ecology, Mrs. Rebka. They bloom, flourish, and die back, only to repeat the cycle again, over and over."
"By the Hypotheticals," Dr. Dvali said, "I presume you mean their machines."
"That may not be a meaningful distinction. There's no evidence that their self-reproducing machines are under the control of anything but their own networked intelligence and their own contingent evolution.
Naturally, the detritus of their lives circulates through the solar system. Periodically the debris is captured by the gravitation of an inner planet."
"Why haven't these things fallen on the Earth?"
"Before the Spin the Earth existed in a much younger solar system Five billion years ago the Hypotheticals had barely established themselves in the Kuiper Belt. If their machines did occasionally enter the Earths atmosphere it would have been an isolated, rare event. There are enough reports of hovering lights or strange aerial objects to suggest that perhaps it did happen, now and then, though no one recognized it as such. When the Spin barrier was put in place it excluded any such fall-through, and even now the Earth is protected from the excessive radiation of the sun by a different kind of membrane. Mars, for good or ill, is more exposed. Martians didn't arrive in the modern day as strangers, Dr. Dvali. We've grown and evolved for millennia with the knowledge that the Hypotheticals exist and that the solar system is, in effect, their property."
"The ash that fell on us," Mrs. Rebka said, her voice throaty with a kind of hostile urgency, "was that the same phenomenon?"
"Presumably. And the growths in the desert. It's only natural to assume that this solar system has also hosted Hypotheticals for countless centuries. The annual meteor showers are more likely their detritus than the simple remains of ancient rocks. The ashfall was just a particularly dense example, perhaps from a recent exfoliation. As if we had passed through a cloud of, of—"
"Of their discarded cells," Dr. Dvali said.
"Cells, in a sense, shed, perhaps discarded, but not necessarily inert or entirely dead. Some partial metabolism persists." Hence the ocular rose and the other abortive, short-lived growths.
"Your people must have studied these remains."
"Oh yes," Sulean said. "In fact we cultivated them. Much of our biological technology was derived from the study of them. Even the longevity treatment is remotely derived from Hypothetical sources. Most of our pharmaceuticals entail some element of Hypothetical technology—that's why we grow them at cryogenic temperatures, simulating the outer solar system."
"And the Martian boy—and Isaac as well, I suppose—"
"The treatment they received is much more closely related to the raw matter of Hypothetical devices. I suppose you thought it was some purely human pharmaceutical? Another example of marvelous Martian biotech? And in a sense it is. But it's something more, too. Something inhuman, inherently uncontrollable."
"And yet Wun Ngo Wen brought the seed stock to Earth."
"If Wun had discovered the older, wiser culture we all assumed must exist on Earth, I'm sure he would have been frank about the origins of it. But he found something quite different, unfortunately. He entrusted many of our secrets to Jason Lawton, who rashly experimented on himself—and Jason Lawton circulated the secrets to people he trusted, who proved no more prudent."
Sulean was aware of the shock in the room. These were names, Wun Ngo Wen and Jason Lawton, reverently spoken among Terrestrial Fourths. But they were mortal men, after all. Susceptible to doubt, fear, greed, and hasty decisions repented at leisure.
"Still," Dr. Dvali said at last, "your people could have told us—"
"These are Fourth things!" Sulean was surprised by the vehemence in her own voice. "You don't understand. It's not zuret—" She couldn't exactly translate the word and all its nuances. "It's not correct, it's not proper, to share them with the unaltered. The unaltered don't want to know; these things are for the very old to worry about; by accepting the burden of longevity they accept this burden too. But I would have shared them with you, Dr. Dvali, before you began this project, if you hadn't hidden yourself so well."