Ultima (43 page)

“More like four and a half,” the ColU said.

Stef squinted. “So if that beast, which is around two hundred thousand light-years across, is
that
apparent size in the sky, I could estimate its current distance—”

“Done,” the ColU said. “Colonel Kalinski, I now know we have traveled—or rather the Hatches have taken us—some three and a half billion years into the future. That is, after the epoch from which we set out.”

Beth, Mardina, Chu just stared at each other, and then into the slate hanging from Chu's neck, as if the ColU's mind resided there, as if behind a human eye.

But Stef understood immediately. “Yes, yes. So the collision is still a billion years away—”

“If it were to happen at all,” the ColU said enigmatically.

“I wonder what it must have done to cultures that emerged after our own, to have
that
hanging in the sky. Growing larger century by century. How many religions rose and fell in its light, awed and terrified?”

“We'll never know, Stef Kalinski,” the ColU murmured.

“And, over three billion years—that's presumably more than enough time for all the processes we've seen here on Per Ardua to have come about. For almost every trace of humanity to have eroded away. Even for species from two different star systems to find a way to evolve into one.”

Mardina looked around the strange sky. “I don't understand. Three and a half billion years . . . It's meaningless. Where is Terra? Where's the sun?”

“I'm afraid I'm not sure,” the ColU said. “The sun and the Alpha Centauri system, the Centaur's Hoof, were once near neighbors. But by now they will have wandered far from each other, as the Galaxy has turned on its axis. Earth, Terra, and the other planets will still orbit the sun. But Earth is probably lifeless; the sun, slowly heating, will have sterilized the inner planets—oh, as much as two or three billion years ago. But the aging sun has not yet entered its terminal cycle, the red giant phase when the sun will swell and swallow the inner worlds.”

Earth lifeless.
Suddenly Stef shivered, despite the comparative warmth of her clothing. To be alone on this world was one thing. To be taken out of one reality stream and dumped in another was extraordinary. But to be stranded in a future so remote that Earth was dead, that presumably nothing like the humanity she had known could still survive . . .

“This is terrifying,” she murmured.

“Indeed, Colonel Kalinski,” the ColU said.

Chu was looking around the sky. “I rode on starships,” he said slowly. “I was held in slave pens. But when I passed windows, I glimpsed the skies of many worlds. And this is quite different. I mean, even aside from the approaching star storm, Andromeda. The stars seem more dim, more sparse.”

“That's a good observation,” the ColU said. “Even in our time the great ages of star making were ending. Now there are fewer young stars, more aging ones.”

Chu asked, “And where are the other stars of the Centaur's Hoof? They should be two brilliant lanterns in the sky.”

“Even Alpha Centauri has evolved with time,” the ColU said sadly. “Its stars were older than the sun. The brightest of the main pair will have lapsed into its red giant stage perhaps half a billion years ago, sterilizing any worlds in its own system, and its partner's, before collapsing to a white dwarf—and Proxima will have become decoupled from its weakening gravity field. The lesser of the main pair would have had many billions of years left before it, too, entered its terminal phase. Smaller stars last longer. Proxima, the runt of the litter, would likely have lasted for six
trillion
years before running out of its carefully processed hydrogen fuel. But Proxima, now, is alone.”

“You say
would
,” Stef said. “
Would
have lasted trillions of years. And you seemed remarkably precise in your estimate of the date, given only a cursory look at this sky above us—”

“As I told you, I do have more information,” the ColU said. “About the future of the universe, gathered during the long years of my journey home to Earth in the
Malleus Jesu.
Subtle signs of times to come: evidence of titanic future events, smeared across the sky of the present. Events whose date I was able to estimate. Once I saw that Andromeda was so close, once I realized roughly what epoch this is, it was easy to deduce that they would have brought us, not to some arbitrary earlier point, but to
this
point in time. This most special time of all. With more observation, especially of the cosmic background radiation, I will be able to be more precise still—”

“They,”
Stef snapped. “
They
brought us here. You mean the Hatch builders. Who Earthshine called the Dreamers.”

“The Dreamers—yes.”

Chu asked now, “And what is so special about this time, this future, this age?”

“Nothing.” The ColU sighed. “Nothing, save that it is the last age of all.”

“The End Time,” Stef said.

She saw Mardina place her hand on her belly, over her unborn child.

That was when Titus and Clodia came clambering up the slope. “
Here
you are. Camp discipline: leave a note before you all clear off next time.”

Beth said, “We're stargazing. Looking at
that
.” She pointed up at Andromeda.

Titus snorted. “Who cares about lights in the sky? I've got something much more important to show you. Come see what we found!”

It was a walk of around three kilometers—two of Titus's Roman miles.

They came down off the flank of the mountain and made their way along a dry, shadowed valley. The going was easy, even for Stef, who had walked little save around one campsite after another since the expedition set off. Titus and Clodia both carried torches of dry stems bundled up and dipped in pots of marrow; they burned, if fitfully. But the glow from Andromeda was surprisingly bright, especially from that brilliant central core. Billions of suns in lieu of moonlight, Stef thought idly.

And, as Titus had predicted, when she came to the structure Titus and Clodia had found, Stef too forgot the wonders of the sky. She even forgot, for a while, the ColU's dark and still obscure mutterings about the End Time.

It was another ellipse, tilted like Andromeda in the sky—but this one, much longer than it was wide, was cut into the ground. And as Stef approached the cut she saw that in fact she was looking into a circular tube, a cylinder—no, a tunnel; it was big enough to be called that—several meters in diameter, that slid into the ground at a shallow angle, making this elliptical cross-section where it met the flat ground surface.

The ColU had his bearer, Chu, walk around this formation, studying it closely.

But Titus warned them all sternly not to step into the tunnel, onto the smooth, curved interior. “We were wandering around at random, hoping to find a convenient river or some such to carry us further on our way . . . Then we found a kind of way marker. Solid granite, and barely eroded.”

“We are all but beyond the terminator weather here,” the ColU said. “Weathering, erosion, will be slow. The marker, like this structure, could be extremely old.”

“Well, the marker had a distinctive arrow; you couldn't mistake its meaning. Which led us straight to this.”

“Remarkable,” the ColU said. “Remarkable. And for us to have happened on such a structure so close to where we crossed the terminator—it cannot be chance; the cold side of this world must be laced with such constructs.”

“I don't understand,” said Stef. She walked closer to the ellipse lip. “I see a tunnel.” She glanced back at their mountain for reference. “Pointing pretty much southeast—that is, away from the substellar—”

“And directly toward the antistellar,” the ColU said.

“A tunnel sloping down at a pretty shallow angle.” She took Clodia's torch and held it up. The tunnel continued dead straight, into the ground, beyond the glow cast by the flickering torch. “Some kind of transport system?”

Titus grinned. “You philosophers haven't spotted the most interesting thing about it. I told you to stay off the surface. Why? Because it is perfectly slippery—less friction than the smoothest ice, I would say. Though I can tell you it is no colder than the rest of the world—I touched it with my hand; I dared that. But if you were to step on it—” He took a pebble and set it carefully on the sloping surface of the cylinder. It seemed to rest still, just for a moment, and then began to slide into the mouth of the cylinder, picking up speed gradually until it disappeared into the shadows. “See?” Titus grinned. “You would fall on your backside and you would slither off out of sight, forever.”

“Not forever,” the ColU said. “Titus, I daresay you've tried this experiment a few times. When exactly did you drop your first rock down this shaft?”

“Actually it was a spare torch. I wanted to see how far it extended . . .”

They compared times. Titus always kept a careful check on times when marching or scouting. He had dropped the torch about an hour and fifteen minutes earlier.

“Good,” said the ColU. “We won't have long to wait.”

Stef frowned. “Wait for what? This enigmatic manner of yours is irritating, ColU.”

“I'm sorry. When I was a mere farm machine, you know, people rarely listened to my speculations—”

“Spill it, tin man.”

“Colonel Kalinski, I think this is a gravity tunnel. It's an old idea, dating back to contemporaries of Newton.”

“Never mind the history lesson. Just
tell
us.”

“Imagine a tunnel dug
through the ground
, in a dead straight line between two points on a planet's curving surface. The tunnel is straight, but you can see that it will
seem
to dive down into the ground at one point, and then climb up again at the destination.”

Stef nodded. “I get it. So if you line the tunnel with a frictionless surface, and climbed on a sled—”

“You would slide down into the ground, reaching some maximum speed at the midpoint of the tunnel, until slowing to the other end. It would feel as if you had descended a slope and climbed another, but in fact you would have followed the tunnel's straight line all the way. Do you see, Stef Kalinski? The passage is energy free, once the tunnel is cut. Powered by gravity alone. And if you built a network of tunnels, and made them durable enough—”

“You've built a transport system that could last a billion years.” Stef grinned at the audacity of it. “All but indestructible, and free. I love it. So the people who built this, whether they were our descendants or not, must have been pretty smart.”

The ColU said, “They may not have been people at all. This is Per Ardua. Remember we had evidence that there was a builder Culture that achieved planetary engineering. Maybe this is somehow a legacy of that.”

Titus was frowning. “I am trying to work this out. So my torch will have slid along this tunnel to the terminus. And then, with nobody to collect it—or so I presume—it will have started to slide straight back again. You say we must wait only a few minutes, ColU. Do you mean until my torch returns? But how can you know that? You don't know how
long
this tunnel is . . .”

“It doesn't matter,” the ColU said. “It's an odd quirk of physics. The time the journey takes only depends on the density of the planet, the gravitational constant . . . Even if you could cut a tunnel right through the center of the planet—”

“Which would have been handy getting from substellar to antistellar,” Stef said drily.

“Even then, though you'd have reached much higher speeds at the midpoint, the journey time there and back would be the same.”

Titus said, “All this sounds like philosophical trickery to me. And how long is this magic transport time you predict, O glass demon?”

The ColU said, “Just wait . . . About
this
long.”

And, right on cue, a bundle of reeds came sliding up out of the mouth of the tunnel. As it slowed to a halt, Titus carefully reached down and swept it up with his one good hand. “Ha! A fine trick, demon. But now we have some planning to do. Come! Let us return to camp.”

•   •   •

The first trip through the gravity tunnel, Titus decreed, was to be made by sled, Beth's cart, with the runners they had made to replace the axles and wheels on the undersurface. Of course they had anticipated having to drag the cart over farside ice, but Stef could see that this arrangement ought to work even better in the frictionless tunnel.

So they wheeled the cart the couple of miles to the tunnel mouth, established a temporary camp, spent a day fixing up the cart with its sled rails. They ate and slept, according to Titus's stern orders.

Titus decreed that the first to take a trial trip through the tunnel would be himself with his daughter Clodia—and the ColU and Stef, who might be able to interpret the experience, and what they found on the far side. The pregnant Mardina, the baby's father, Chu, and prospective grandmother Beth, would not be split up come what may; they would be staying behind.

They were evidently going to have to do some fancy work getting the crew loaded on at one end of the tunnel, and successfully off at the other before the sled started to fall back, without any outside help. Before they hauled the cart over to the tunnel Titus had them practice the art. They had most success with Titus and Clodia leaping out at the destination, carrying rope to tie up the cart, while Stef stayed in the cart cradling the ColU.

Then the cart crew bundled up in their warmest gear—they were after all going an unknown distance deeper into the chill of farside—and loaded food, water, blankets, material for a fire, and a few of their precious tools, onto the cart itself. Beth, Mardina and Chu had an easy enough time pushing the cart over the lip of the sloping tunnel, and held it steady while the passengers climbed aboard.

Then Titus ceremoniously lit a torch and held it aloft. “Onward, and into the unknown!”

The support crew let go of the cart. Slowly, almost imperceptibly, it began to slip down the slope.

Stef glanced back at the grinning, somewhat anxious faces of her companions. “It's taking an embarrassingly long time to get going,” she said. “I feel like the King of Angleterre in his coronation carriage.”

“We will be in the dark soon enough,” the ColU said. “But remember, even if the torch were to fail, it is only forty minutes to complete the one-way trip to the far end.”

Now the mouth of the tunnel was all around them, swallowing them up, their speed gradually increasing. The dark was deepening now. The movement was utterly smooth, and entirely silent.

Stef felt a frisson of fear. “It's like a roller-coaster ride. Magic Mountain at Disneyland. None of you have the faintest idea what I'm talking about, do you?”

Titus, cradling his torch with his burly body, was suspicious. “I don't understand. We are moving quite rapidly already. And yet there is not a breath of wind.”

“As I anticipated,” the ColU said smoothly.

Stef snarled, “What now, ColU? I wish you'd be open with us.”

“I apologize, Colonel Kalinski. There could be no air resistance in here. Otherwise, you see, the friction would slow us; we might pass the midpoint but would not reach the tunnel end, and would slip back, eventually settling at the center, the lowest point. Human engineering designs based on this idea always imagined a vacuum tunnel.”

Titus took a deep breath. “We're in no vacuum.”

“I think there is an invisible subtlety to the design. The air we breathe is carried with us—perhaps the tunnel air is held aside. Given time, Stef Kalinski, you and I could no doubt investigate the engineering. Whatever the detail, it must be robust to have survived a billion years . . .”

The dark was deep now. They didn't seem to be moving at all, and Stef soon lost track of time. In the light of the torch, Clodia cuddled closer to her father.

Stef, unable to resist it, moved closer to the big Roman too.

Titus said, “I am sorry I do not have a hand for you to hold, Stef.”

She clutched his stump of an arm and rested her head on his shoulder. “This will do.”

“It won't be long,” the ColU murmured, from the dark. “Just forty minutes. Not long.”

•   •   •

They emerged on an icebound plain.

Stef walked a few steps, away from the tunnel mouth and the disgorged cart. She swung her arms, breathing in deeply; the cold stung her mouth, and her breath steamed. “This is the far side, all right. Just the way I remember it.”

She looked around. Andromeda still hung huge and looming in a crystal-clear sky; there wasn't a shred of terminator-weather cloud here. In the crimson galaxy light, the land seemed featureless, flat. But there was a peculiarly symmetrical hillock in the ice a few hundred meters away, like a flattened cone, or a pyramid with multiple flat sides—or like a tremendous jewel, she thought. Could it be artificial? There was no other feature in the landscape to draw her eye.

She walked that way, trying to place her booted feet on ridges in the ice to avoid slipping.

Inevitably Titus called after her. “Don't go too far!”

She snorted. “I'm hardly likely to have marauding barbarians leap out at me, legionary.”

“You might slip and break your brittle old-lady bones. And with my single arm it would be a chore for me to have to carry you back to the cart and haul you home.”

“I'll try to be considerate.”

The ColU called, “In fact, Colonel Kalinski, would you mind carrying my slate for a closer inspection? And if you could find a way to bring back a sample of that formation . . .” With surprising grace on the ice, Clodia jogged out to hand Stef the slate, and a small hammer from their rudimentary tool kit.

As Stef approached the pyramidal structure, she listened to the ColU's analysis.

“I can deduce our change in position quite clearly from the shift in the visible stars' position. Andromeda has shifted too of course, but that is too large and messy an object to yield a precise reading . . .”

The closer she got, the less like a geological formation the pyramid seemed. It was too precise, too sharply defined for that. She supposed there might be a comparison with something like a quartz crystal. But she had an instinct that there was biology at work here, something more than mere physics and chemistry. She took panoramic and close-up images. The pyramid looked spectacular and utterly alien, sitting as it was beneath a sky full of galaxy. Then she bent to chip off a sample from one gleaming, perfect edge.

Titus called, “How far have we traveled then, glass demon?”

“Not very far at all, Titus Valerius. Only a hundred kilometers—just a little more. That's perhaps sixty Roman miles. Not very far—but that means we were never very deep under the surface. Two hundred meters at the lowest point, perhaps.”

With her sample of what felt like water ice tucked into an outer pocket, Stef headed carefully back to the group.

“Not very far, as you say, demon. But we know this tunnel is not the only one of its kind in the planet.”

“Quite so, legionary. There will be many such links, perhaps a whole network, perhaps of varying lengths.”

“Yes. And a way for us to go on, deeper into the dark. There must be another entrance close by—all we need do is find it. And then—”