After Jupiter, Falcon returned to Port Van Allen, and to other retreats.
He wrote, read, reflected. Sometimes he travelled, even explored new worlds, new terrains. And periodically he was drawn back into the brusque care of Hope Dhoni, a scion of a vanished dynasty like himself, as ageless as he was, and yet, somehow, in her inner strength and determination, and in her devotion to Falcon himself, far more enduring.
More years, more decades, rolling like tides across the worlds of human and Machine. As the Machines’ half-millennium slowly unwound, he waited to be called into the fray once more.
And when, more than a century after the Nantucket affair, that call did come, it was to a small, hazardous, angry world even he had never visited before.
* * * *
Chief Administrator Susan Borowski briskly led Falcon through an airlock set in the outer dome of Vulcanopolis, capital of the Free Republic of Mercury. They emerged into a night-time landscape of shattered rock and craters, under a star-littered sky. A black sky, even though Mercury was less than half the distance of Earth and Moon from the sun. The perpetual shadow of a polar crater’s walls protected Vulcanopolis and its people from the direct light—the sun never rose here—but even from here Falcon could see a corona flaring above walls of rock. This was why he was here, in a sense, why he had raced across the solar system in a warship called the Acheron. There was something wrong with Mercury’s sun. It was all the fault of the Machines. Already more than a century since Adam’s declaration of war, Howard Falcon was still the nearest mankind had to an ambassador to the Machines. And an audience had been requested here on Mercury.
He felt oddly detached from the situation, urgent as he’d been told it was. It wasn’t an uncommon feeling for him these days. Oddly detached? Oddly old. Well, it was more than three centuries since his birth now; how was he supposed to feel? Years, even decades seemed to pass in a blur, leaving barely a trace in his capacious, cluttered memory. A full century after the Jupiter Ultimatum, Howard Falcon was becoming adrift, floating like a balloon in clouds of unstructured time.
But—whatever reason had brought him—here was Howard Falcon, rolling along a gravel track on the surface of yet another new world. How many was it now? His only personal first footfall, so to speak, had been on Jupiter, but to be the John Young of the world’s mightiest planet was not an achievement to be sneezed at . . .
As he wool-gathered, Falcon could see Borowski smiling at him, her face illuminated behind her visor. He tried to focus on the here and now.
Borowski said now, “Sorry we had to come out through a cargo bay door. It’s the only one that would fit. It was that or dismantle you.”
This was what passed among the Hermians for humour, Falcon was learning. “Oh, I wouldn’t put you to any trouble. And the track’s comfortable.”
“Comfortable, Commander? Evidently we haven’t been working you hard enough. Come on.”
Abruptly she veered off down a trail marked by lanterns embedded in the gritty dust, leading towards the crater-rim mountains that shadowed the sun. In that shadow Falcon made out a cluster of lights: it was one of Messenger Crater’s many mines, here to extract the treasure that had motivated the establishment of Vulcanopolis in the first place—water ice.
Falcon followed more cautiously.
You had to take the Hermians at face value. Like all inhabitants of low-gravity worlds they tended to be tall, spindly, often wiry but physically fragile—but they thought of themselves as uniquely tough, and they expected offworlders to keep up. Then again, this was perhaps the harshest environment from which any humans had yet tried to wrest a living. Mercury’s “day” of fifty-nine Earth days was two-thirds of its “year” of eighty-eight days, a resonance created by the sun’s tidal tweaking: a combination that meant that any point on Mercury’s equator, between sunrise and sunset, would endure a blistering one hundred and seventy-six Earth days of continuous sunlight, during which the surface temperature became hot enough to melt lead and zinc.
But for once nature had given mankind an even break. Mercury, unlike Earth, had no axial tilt; its poles pointed perpendicularly out of its plane of orbit. As a result the floor of a crater placed precisely at either pole—which pretty much described this crater, Messenger—never saw the sun at all. And in the unending shadow of those crater walls, over millions of years, water and other volatiles, delivered sporadically by the splash of comets, could condense out, collect, and freeze. That was the basis of the economy of Vulcanopolis. The comet-ice water mined here was pumped to equatorial cities like Inferno and Prime, which in return fed back energy collected from the sun by sprawling solar-cell farms.
Borowski said now, “I hope Bill gave you a heads-up on this little expedition.”
“Bill? Oh, Jennings, your—umm, Vice-Chief Administrator. On any other world, poor Bill Jennings would glory in the title of Vice President.”
She laughed. “You can blame my predecessors for that. When the Treaty of Phobos was signed back in ’15 Jack Harker decided he’d like to keep his old Interplanetary Relations Bureau job title. It amused him, I think. So ‘Chief Administrator’ he remained.”
It took Falcon a moment to do the maths; dates were slippery for him these days. In the aftermath of the Machines’ Jupiter Ultimatum, Earth had quickly recognised the colony worlds as free states: the World Government had decided it needed stronger allies more than it needed resentful colonies. The Phobos convention had met in the year 2315—a date chosen for its resonance with the signing of the Magna Carta in 1215, and now Martian barons liked to brag they had brought a Terran king to heel. And today’s date, May 11, 2391, had long been engraved into Falcon’s mind for another resonance: it was the date of a transit of Mercury as seen from Earth. So, from 2315 to 2391—
“Oh, come on. The Phobos deal was seventy-six years ago!”
“We Hermians don’t make many jokes. When we come up with a good one we keep it . . .” The path was steepening sharply. “You okay on this gradient? Until the Machines came we used to run a funicular for the tourists: one of the seven wonders of the solar system, or so our ads claimed.”
“I’ll be fine.”
“We’ll be in sunlight soon. Check out your suit.” She tapped a panel on her chest. The front of her own suit silvered and the back turned dark, a chameleon-like adaptation that would, Falcon knew, respond to a change of position so that she always kept her mirrored side to the solar glare, the heat-dumping dark side turned away. Meanwhile extraordinary wings folded out from a backpack, so that she looked like some overgrown, silvery bat. The wings were radiator panels, more thermal control.
Falcon inspected his own clumsier systems. There was, of course, no human-issue suit that would fit Falcon. But the Hermian engineers, who famously relished a challenge, had swarmed over the latest iteration of his prosthetic carriage, checking the integrity of his basic life-support systems, swaddling him in protective thermal blankets, and fitting an adapted set of radiator wings and other systems to his frame. It would never be as elegant as Borowski’s suit, which was the product of more than three centuries of technological evolution since the first landings here—but, the engineers told him, it would keep him alive long enough to get to shelter if anything went wrong. A pragmatic if not entirely reassuring promise.
And while he was distracted by the unfolding of his wings, Howard Falcon rolled into sunlight. His optical shields immediately cut in, reducing the brilliance to a mere dazzle. The mighty sun glared over a sharp, crumpled horizon. From this elevation Falcon looked out over a plain of broken rock, across which long shadows stretched. Superficially this world was Moon-like; a world scarred by craters, the relics of impacts dating back to the solar system’s violent formation. But Falcon had been to the Moon many times—at least, before the Machines had moved in—and he could see significant differences. The crater walls seemed visibly less steep, perhaps a product of Mercury’s higher gravity and the inner heat of its larger, molten core. And Falcon saw a twisting line of cliff faces, almost like a wrinkle in the landscape that cast a band of shadow within which more artificial lights huddled. Such features, called rupes, were the relics of episodes in which Mercury, its inner heat dissipating, had shrunk, leaving its skin a little like that of a withered apple.
Above it all hung the sun, more than twice its width as seen from Earth, but with around seven times the intensity. Falcon seemed to feel that tremendous outpouring, just standing here. It was impossible to reconcile the physical force of the star’s presence with the pale thing he remembered from the winter mornings of his childhood in England, as if the sun barely mustered the energy to lift itself above the horizon. It was that monstrous flow of energy that had made Mercury a key colonisation target, first for humans—and latterly for the Machines. The sun: star of humanity and of the solar system, and now a prize of war.
He was aware of Borowski watching him. She said, “You know, a lot of people just don’t get Mercury. Or us Hermians, come to that. Even though we’re such a jolly bunch.”
Falcon smiled. “I looked you up. During the Phobos negotiations your ambassador’s ‘irascibility’ was actually minuted.”
She looked out over her world of rock and raw energy. “Earth is a pretty alien place for us, you know. Mars, though, we have something in common with. We have dreams of terraforming too. Or we did. You’re surprised? It would be a big job. You’d need to shield the planet from the sunlight, spin it up to give a sensible day-night cycle, import volatiles for oceans and an atmosphere.”
“I thought most Hermians liked the place the way it is.”
“Well, I’m among them, but you have to think of the future. You need a long-term habitability solution, just in case your children forget how to maintain the air engines. That was the ambition, anyhow.”
Falcon nodded. “But here are the Machines taking all that away from you.”
Borowski squinted up at the sun, its fierce light flattening the planes of her face. “The shield isn’t yet visible to the naked eye, but you can already measure the dip in the solar energy reaching the planet. And you can see it with a bit of visual processing: a kind of web hanging right in front of the sun, a bit larger than Mercury’s diameter; a hell of a thing, and yet, according to our spy probes, gossamer thin. Mostly aluminium—Mercury aluminium, and that theft pisses me off greatly.”
“I don’t understand how the shield is being kept in position, up there in space. You have the pressure of sunlight, and Mercury’s gravity pulling it down to the planet—”
She pointed back over his shoulder. “There’s a secondary structure back there, even bigger than the shield itself. It’s a mirror, Commander—an annulus, a circular band, with a hole you could slide Mercury through, literally.”
Falcon the engineer peered up in wonder. “So the shield blocks the light from Mercury. But the sunlight that passes the shield hits this mirror, and is reflected back to hold the shield itself in place, pushing against the gravity and direct sunlight.”
“You’ve got it. The whole thing is one vast engine, using gravity and beams of sunlight as girders.”
“I wish I could see it.”
She laughed. “Now you sound like a Hermian. Of course there’s more to it than that. Mercury’s orbit is strongly elliptical, and the shifting solar and planetary tides disturb the set-up—it needs a lot of station-keeping. But we know that both shield and mirror are composed of Machines, which are individually pretty smart, and a swarm of them will be that much smarter again. Working en masse their components are able to sense their positions, compensate for the shift in balance of the competing forces.
“For now, most of the sunlight still gets through, but it won’t stay that way; the holes are being filled in. My engineers tell me that the final phase will be very rapid—that’s in the nature of exponential growth. We’ll see the sun go dark in a day. Cutting off the sunlight on which we depend for everything.
“Anyhow, it’s nice to know we Hermians have friends at our backs as we face this crisis.” She glanced at him sourly. “Friends from Earth. One warship. And you.”
He spread his hands. “The World Government is a cumbersome beast that’s slow to respond to a crisis. But the people of Earth are right behind you. That’s why the Acheron timed its mission to arrive today.”
She grunted. “For the coincidence of the transit.”
“Well, it’s only a partial transit, but the timing is apt.” He turned and pointed, directly away from the sun. “Today, Mercury happens to lie on a straight line between sun and Earth. And if you were standing on Earth you could see the planet’s shadow crossing the face of the sun . . . All over the world, people are looking up at Mercury, right now, looking at us. President Soames is big on symbolism.”
“Great. But what are you Terrans going to do?”
“Whatever we can.”
Which, Falcon admitted, had been little enough so far.
* * * *
For an old stager like Falcon, it had been a surprise when the Ultimatum’s centenary had suddenly arrived, marked by grim headlines and analyses.
But even in an age when extreme longevity was becoming routine, the making of a threat to be fulfilled five centuries hence—perhaps twenty old-fashioned human generations away—seemed beyond the capacity of most people to comprehend. It didn’t help to focus minds that at first the Machines had appeared to do nothing more threatening than to suspend shipments of Jovian helium-3 and other products to Earth.
The authorities had responded, however. Saturn, the second of the solar system’s gas giants, had been fast-tracked as an alternate source of fusion fuel. Back home, great new projects were afoot. Falcon had been fascinated by plans to erect space elevators around the equator of Earth, beanstalks that would allow fast and cheap access to space on a massive scale—and would provide a fast mass evacuation route, if it came to that.
But behind the scenes, successive administrations had put more subtle measures in place to respond to the Ultimatum. The Phobos Treaty had been one step. Meanwhile a new Planetary Security Secretariat had been established—a typical bureaucratic response, people had grumbled at the time, but it had laid down some useful groundwork.
Despite all the strategic thinking and wargaming, however, it had still taken everybody by surprise, Falcon thought, when, over a century after the Ultimatum, the Machines had finally made their first significant move with this assault on Mercury. And it had led to predictable demands that the World Government do something about it.
Falcon, semi-detached from humanity himself, rather resented having been drawn into Planetary Security’s covert plans in response. Yet here he was, standing in the Hermian sunlight.
Borowski said now, “The Machine ships came in at superspeed. Better than anything we’ve got. Even the warning from Spaceguard got to us only a little before the vanguard arrived. Some of our technical analysts think the Machines have got what they call an ‘asymptotic drive.’ Do you know the theory? You throw matter into a miniature black hole, and as it’s crushed out of existence you get a pulse of energy that can drive a spacecraft. But you’d need some way of manufacturing miniature black holes to make it work . . .”
Uneasily, Falcon remembered Adam’s talk of the Machine he called 90, and the radically new physics he had dreamed up out in the dark, surrounded by a spinning sky . . . From that, perhaps, something like the asymptotic drive might have come.
However they were powered, nothing had been able to catch the Machine ships.
“They landed at Inferno,” Borowski said. “Second city on Mercury, slap bang in the middle of the Caloris Basin.”
Falcon nodded. Caloris was a mighty impact crater that sprawled across much of one hemisphere of Mercury. “They would land there. Machines have a sense of symbolism too—or at least of symmetry.”
“They started their construction work on day one. We saw it from surveillance satellites. Their ships just dissolved, melting down into subcomponents that started chewing the rock . . .”
“Assemblers.”
“Yeah.”
Falcon knew the theory of this kind of engineering. Assemblers were von Neumann replicators, a variety of specialised Machines that had used Mercury’s sunlight and minerals to make copies of themselves: Machines that fed on planets, like flesh-eating bacteria. From the beginning the assemblers had been firing material up into space to build what had become their huge spaceborne construction project, the sunshield hovering over Mercury. Also, for reasons as yet unknown, they were firing clusters of probes across space—not towards Earth, but, bafflingly, to Venus.
Borowski pointed at the sun. “Everything we do here depends on solar energy. And now the Machines are using that very energy to build the shield, their weapon against us.”
“What do you think their ultimate goal is?”
Borowski shrugged. “Isn’t it obvious? The Machines have come here for the same reasons humans did. Mercury is a rich lode of raw materials, handily positioned as close as you can get to the solar system’s powerhouse. I’d predict we’ll see large-scale resources extraction starting up soon, maybe manufacturing.”
Falcon knew the Machines; he doubted their ambitions would be so limited.
“The Machines have left our people at Inferno unharmed. They’ve allowed evacuation of children, families, the ill, even passage of essential supplies. But this will be the end of Prime, Vulcanopolis, Inferno—the end of us.”
Falcon could hear her pain, and imagined how difficult it must have been for the tough, noisily self-reliant Hermians to have to reach out to the other worlds, to that resented mother Earth. “President Soames is going to make a speech later.” Even as he said that, he could hear how lame it sounded.
Borowski just laughed. “I told you, I’ve been to Earth. I’ll tell you what I saw, Commander. I saw a world like a garden. A park. All those cities like museums, the restored animals. Everything’s free,” she said with disgust. “You Terrans are soft.”
He sighed. “Maybe. But we’re behind you.”
“You have to be. Because if they get past us, they’ll be coming for you.” She glanced up at the sun, occluded by a spider web neither of them could see. “We’re done here.” She turned on her heel and led him back down the crater-mountain path and into shadow.
Later that day a message arrived for Falcon, followed by a requisition order for a sub-orbital shuttle. Adam had agreed to meet him in Caloris Basin.