Stef frowned. “I’m not sure I understand. You don’t have to construct the Hatch?”
“No more than we have to ‘construct’ a chicken emerging from the egg. Our druidh speculate that there is a Hatch implicit in the form of every kernel. It is merely a question of breaking the egg to release the chick, to use the kernels’ own energy to shock one of their brood to adopt this new form. You never discovered this?”
“My culture was more cautious than yours. More timid, perhaps. We would never have won approval for such an experiment.” For better or worse, she thought, we cared more about the lives of our technicians than to spend them on such stunts. Even if it had occurred to us to try. “How did you get the idea? I can hardly believe you found such a specific arrangement by trial and error.”
Eilidh smiled. “We did not. Somebody else found it for us.” Now the cetus was rising, turning its prow to the jagged row of mountains on the misty horizon. “We first found the kernels on Mercury—as did you, yes? We were already traveling beyond Terra—well, obviously. We had big ships driven by Xin fire-of-life, and by potent liquid elixirs… I fear our common vocabulary is not yet rich enough.”
Gunpowder and chemical propellants. “I get the idea.”
“Such substances had been discovered and developed during centuries of war. We had already flown to Luna, to Mars, though many died in those days, and our first attempts to plant colonia on those bodies were often catastrophic…”
Stef’s head swam. Without the fall of Rome in the west, without the Dark Ages, could technological development have been that much faster? She imagined a medieval world with crude rocketships lumbering into space, with lessons slowly being learned about the vacuum of space, about radiation, about weightlessness, by cultures utterly unsophisticated in the relevant science—lessons learned the hard way, at the expense of many deaths. She was thrilled at the idea. Thrilled and appalled.
“Then came Mercury,” Eilidh said. “There was a war of acquisition, more intense than most. We all wanted Mercury and its resources to capture the energy of the sun, you see. It was seen as a strategic position in terms of advantage for the future. And just how strategic only became clear when a Xin party stumbled across a field of kernels.”
“Ah.”
“After the usual blood toll the kernels were tamed, their energies used to drive our ships, and they were unleashed as weapons of war.”
That simple phrase managed to shock Stef, despite all she’d witnessed in her own home timeline. “Surely not on Earth itself.”
Eilidh just returned her look. “But we are speaking of the Hatches. The first Hatch of all was found on Mercury, in the kernel field.”
“As it was for us,” Stef said.
Eilidh raised her eyebrows. “On a different Mercury too? We do have much to discuss. Of course the Hatch was opened; of course there were attempts to pass through… None of those who entered, unwilling slaves, bold soldiers, curious philosophers, ever returned.”
“Perhaps they are still in transit.”
“In transit?”
“Our Mercury Hatch is connected to one on Per Ardua. Umm, which is a world of Proxima Centauri. Which is—”
“The nearest star, in the Centaur’s Hoof. For us, it has been given the same name. Proxima.” She smiled, a little sourly. “So there are Romans in your country too.”
“Were. Long story. Look, it’s only four years as light travels between Mercury and Proxima. So it’s possible to go there and step back with only eight years elapsing.”
Eilidh frowned as she puzzled all that out; Stef had no idea how much understanding of such basic physics they shared.
“The point is,” Stef said, “maybe your Hatch on your Mercury was hooked up to somewhere else. Somewhere much farther away.” There was no reason why that shouldn’t be true, she realized. They knew so little, despite the decades that had passed since her own first brush with all this strangeness. “Your travelers may have arrived alive and well, but just haven’t had time to step back home yet. Maybe they are still traveling, oblivious.”
“It’s possible. Oddly there is a soldiers’ legend along those lines. Perhaps the travelers have gone, not to Proxima, the nearest star, but to Ultima, the furthest star of all.”
Stef frowned. What could that mean? The furthest star, in an expanding universe full of galaxies and clusters of galaxies…
“But, though we have not walked through the Hatches to Proxima and its worlds, we have journeyed there in ships—ships like the Malleus Jesu, orbiting high above. When we got there, on the third planet from the star—”
Per Ardua.
“—we found a kernel field, not unlike that on Mercury—by then we had learned how to search for such things—and we found a Hatch, and we found instructions on how to construct a fresh one. Just as I have described.”
“Instructions. Of what kind?”
“Enigmatic. Graphic, but enigmatic. Enough for us to work out the rest, after—”
“Another blood toll.” Stef remembered the builders, natives of Per Ardua—her Per Ardua. She had seen little of them, but she knew Yuri remembered them with affection from his early, near-solitary years on the planet. “These graphic instructions—was there any sign of the natives who created them?”
“None. So I’m told. Not a trace save these odd diagrams, and even they were lodged inside a Hatch.” She eyed Stef. “It was another scrap that doesn’t fit, another fragment of a lost history. Like you and your companions. What do you think?”
A scrap like her own unexpected sister in the Hatch on Mercury, Stef thought. The first reality tweak of all. She shrugged. “I don’t know what to think.”
“Well, keep trying. And now—look down.”
The cetus was now sailing serenely over mountains.
The sun of this world was not high, it might have been an early afternoon at a temperate latitude on Earth, and shadows pooled in the valleys that separated the peaks. The second sun was in the sky too and cast a fainter double shadow. Ice striped the taller peaks, and rivers flowed through the valleys like bands of steel. And, save for the shadow cast by the cetus itself, Stef could see nothing moving down there, no people, no animals, not so much as a thread of smoke.
But everywhere she looked, Stef saw artifice. Every mountain seemed to have been shaped, regularized as a pyramid or a tetrahedron. The valleys looked as if they had been shaped, too, straightened. Some of the peaks were connected by tremendous bridges of stone. Many of the mountain walls were terraced, so that it looked as if giant staircases climbed their flanks, while others had huge vertical structures fixed to their faces, almost like the flying buttresses of medieval cathedrals, or were deeply inscribed with gullies and channels.
Eilidh was watching her. “Tell me what you see.”
“It’s like a simulation.”
“A what?”
“Sorry. Like a model. A mock-up of a mountain range. It doesn’t look real.”
“Yet it is real. This planet is laced by mountain ranges; it is, or at least was, very active. And all of them have been shaped and reshaped by hands unseen, just as you see here. All as far as we have visited and studied. There’s much you can’t see from the surface. We burrowed into one mountain, sounded out others. The mountains are hollowed, strengthened within by huge remnant pillars of rock. They have been transformed into immense granite fortresses, or so it seems. For the Roman military engineers, who eat and breathe fortifications, this is Elysium, as you can imagine.”