Stef smiled at his choice of words. Adventure, not ordeal. The man was a natural leader. Looking around the group, she saw that he held everyone’s attention—everyone save Mardina, perhaps, who seemed unable to eat the cabbage, and was folded over on herself, her knees drawn up to her chest.
“There are six of us, plus the ColU,” Titus said now. “Four of you, all save myself and Clodia, will make one last effort to gather supplies. Clearly nothing will grow on the ice of the dark side, I understand that, so you must gather what you can from the nearside vegetation that grows in the sunlit areas a little way back, or even on the illuminated peak above us. By the time we leave, our cart must be full, our packs bulging. Perhaps we can find a way to reduce more of the food, to boil it, compress it. If the challenge is too much, we can do this more gradually, setting up a series of caches, pushing deeper into the cold.”
Stef put in, “At least we’ll have no trouble with warmth, thanks to the Romans’ kernel oven. There will be no trees growing on the farside ice, no fuel for fires.”
“True,” Titus said.
Beth said, “So while we’re foraging and boiling potatoes, you and Clodia—”
“We will be scouting,” Titus said with a grin. “We’ll go exploring into the dark, a little way at least. Looking for a route forward. And looking for a way to shorten this trip.”
Beth frowned. “How would that be possible?”
“I’ve no idea. But then, I’ve never been here before.” He glanced at the ColU, which sat on a folded-up blanket. “And, in a sense, neither have any of you, since—if I understand your hints correctly—somehow a great span of time separates this world from the one you knew before. Who knows what might have happened in all that time? Perhaps Per Ardua had its own Romans who left behind a road, straight and true as an arrow, leading us straight to the antistellar.”
Stef smiled. “I suppose it’s worth a look.”
Now Titus turned to Clodia. “And I will have you at my side, child, because you will be a valuable companion on such a mission. I’ve seen enough on this journey already to know that.”
“Thanks,” Clodia said flatly.
Titus looked at Mardina. “The alternative is for you to stay here and assist Mardina. You may imagine how much I know about pregnancies. Perhaps it would help Mardina to have another young woman at her side.”
Mardina looked back at him bleakly. “Forget it. My mother’s here. And Stef.”
“And me,” the ColU said. “Remember my programming. I was designed to fulfill the medical needs of a growing colony. Indeed I administered the birth of Beth Eden Jones herself, many years ago. While I am no longer capable of practical intervention, I can—”
“You can shut up,” Mardina snapped at it. “That’s what you can do. I don’t need anything. Not yet.”
Titus glared at her and at Clodia. “At any rate, your rivalry over the boy, Chu Yuen, is over, at least for now. Yes? When the baby comes, you can work out for yourselves how you want to organize your lives, and your loves.”
Stef smiled at him. “Titus Valerius! I’m shocked. I thought you upright Romans were monogamous.”
“Different moralities apply on the battlefield.”
“I wasn’t aware we were on a battlefield.”
“Tell that to the ice. Why, I remember once on campaign—”
“Not now, Father,” Clodia said, and she turned her back.
After a night’s sleep Titus and Clodia bundled themselves up in layers of clothing, packed bags, and slipped away, off to the southeast, deeper into the dark.
The rest got on with collecting foodstuffs and fuel for the fire. Chu, Mardina and Beth explored the diffusely lit valley, and made longer treks back into the lands of daylight. Chu and Mardina also made some climbs up the flank of their mountain, into the island of life and light up there. Beth found the steeper climb all but impossible herself, and she was unhappy about leaving it to her pregnant daughter. But the ColU pointed out the pregnancy was barely begun, its own tests showed that Mardina was as healthy as could be expected, and there was really no reason to hold her back.
Stef assuaged her own guilt by doing what she could at the camp: refurbishing the cart, preparing the food they gathered, fixing meals.
And she worked with the ColU at its studies, biological, geological, astronomical.
The species of vegetation the youngsters brought down from the illuminated summit turned out to be complex. Some of it was familiar, descendants of either Arduan life or terrestrial. But some was stranger, what appeared to be essentially terrestrial root crops but with leaves with a peculiarly Arduan tinge to the green. The ColU grew excited at this, and insisted that Stef dice up samples to be fed into its own small internal laboratory for analysis.
“Do you remember our own trek to the far side with Yuri Eden and Liu Tao, long ago? We passed these terminator islands of light that I longed to explore. I could see even then that such islands really were isolated from each other, especially as we pressed deeper into the dark, just like islands in an ocean. And just as on Earth, islands are natural laboratories for evolution…”
It took it a full day of analysis before it was prepared to announce its conclusions.
The remnant ColU unit had only a tiny display screen, meant for showing internal diagnostics of the AI store itself. Stef squinted to see with tired, rheumy eyes. “That’s a genetic analysis,” she said at last. “But there’s a mixture there. Of terrestrial DNA, and the Arduan equivalent…”
“All from the one plant,” the ColU said. “An unprepossessing tuber that you might trip over in the dark. I’m not even sure if it would be edible, for humans—”
“Just tell me what you found, damn it!”
“Integration. A product of a deep integration of the two biospheres. Colonel, this plant is like a terrestrial vegetable, but with Earth-like photosynthesis replaced by the Per Arduan kind—the version tuned to Proxima light, which exploits the dense infrared energy that Proxima gives off. Do you see? In the very long run, it is as if there have been two origins of life on this world, Stef Kalinski. The first origin was when Arduan life emerged—and we know even that was related to the emergence of life on Earth; there was a deep biochemical linkage enabled by panspermia. And the second origin was when humans arrived at this world—Yuri Eden and Mardina Jones and all the rest—and brought with them a suite of life-forms from Earth.”
“Ah,” Stef said. “The ISF thought they were exploring the stars. In fact they were seeding life.”
“Ever since Lex McGregor walked here and made his speeches, the dual biosphere has been evolving. At first there must have been extinctions on both sides, as forms unable to adapt to the new conditions went to the wall. After that, over a hundred thousand years, a million years, there must have been speciation as new forms emerged and adapted to the new conditions. New kinds of potato, adapted to the thinner Proxima light. And in ten or a hundred million years, there would be time for integrated ecologies to emerge, as the surviving life-forms evolved together.”
“Like the ants in the stromatolite. Like bees and flowers, back on Earth. But this is more, deeper, this mutated metamorphosis. A symbiogenesis,” Stef breathed.
“Exactly. The deepest symbiosis possible, the most intimate life cooperation of all. It is just as the mitochondria in your own body’s cells, Stef, were once independent organisms. They became integrated into your cells to serve as sources of energy, yet they retained their own genetic heredity, a kind of memory of their free-swimming days. Terrestrial life, from amoebas and complex cells upward, is a product of a deep integration of many forms of life. Genesis through symbiosis, indeed.”