by Greg Egan
“Ha!” She gestured at their spartan surroundings.
“This is a job,” Heng replied. “I don’t mind a few small hardships for myself, so long as there’s an end in sight.”
“In twenty years Cydonia will be more liveable than Shanghai,” Akhila boasted, rather implausibly.
“You can send me a postcard when it happens.” He hesitated. “So what’s the attraction for you? Elbow room, or ideology?”
She laughed softly. “Both. Humanity needs a permanent settlement away from Earth, and though some people want to postpone that until our descendants are bitstreams with much lower shipping costs, I don’t think we should pass up the chance we have right now.”
“But you’ll have no relatives on Mars?”
“No, thank goodness.” Akhila smiled. “I come from a family of infuriating meddlers, who delight in being up to their elbows in each other’s business. I love them all, but it’s exhausting. On Mars, I’ll finally have a chance to breathe.”
Heng’s cans chimed with an incoming call. “Please excuse me.” He turned to face the wall.
Liana appeared in front of him, and she wasted no time on pleasantries. “There’s a CME coming,” she said. “We expect the protons to hit you in about fifty-three hours.”
“Is it worth waiting for a later Stone?” Xun asked. “In terms of the eventual reconfiguration?” Heng was impressed by her calm demeanor; he could feel his own jaw locked tight, his own thoughts still trapped in a bitter wail of resentment. Could they shorten their time in exile by a judicious choice of Stone, right now?
“No, there’s nothing to be gained by a delay,” Liana replied. “We’re advising you all to dock with seventeen forty.”
That was the very next Stone they’d encounter, scheduled to catch up with the convoy’s hindmost ship in about four hours. But the Baza was currently leading the pack, and as ever the first would be last.
When Heng made the announcement most of the passengers seemed resigned to their fate. “Is there anything special we need to do to prepare?” Punita asked.
“Everyone needs to be suited in advance,” he said. “I know it’s awkward doing that weightless, but it’s even harder at a gee and a half.”
Heng looked to Darpana. She was dutifully trying to appear solemn, but he could tell that she was excited by the news. They were fleeing for their lives from a surge of radiation – but the race was fixed squarely in their favor, and it would soon reunite her with her beloved cousin. With all the thrill of the chase but no real danger, why shouldn’t she revel in it?
He struggled to quell his own anger and disappointment, to be grateful for the prospect of safety and put the rest of their problems aside. He’d even ended up with a reasonably harmonious group of inmates to share his sentence in the rock; if this had happened on his last run it might have led to civil war.
Noor said, “My parents went around the world twice on their honeymoon, but it looks like I’ll be setting a new family record.”
#
Xun’s ship, the Monal, was the first to dock with their heavenly Alcatraz. Harnessed to his bunk, Heng watched an overlay of telemetry from the ship as it locked onto the whirling cables and then applied its ion thrusters to end its tumbling relative to the rock. Before the cradle had been winched down from the asteroid to start bringing the passengers inside, the Lapwing had joined the Monal on the opposite spoke.
Heng was always nervous when he was approaching a crowded Stone, even if the satisfaction of having reached the mid-stage usually took the edge off it. The navigators had had plenty of time to determine the best spoke for each ship and tweak their precise moments of arrival accordingly, but there was no denying that the safety margins shrank each time another obstacle lodged itself between the cables.
The Snipe docked smoothly, followed by the Curlew. As Heng watched a schematic of the Stone spinning toward the Tragopan he found himself extrapolating the motion in his mind’s eye, picturing the inevitable meshing of ship and reserved parking space. The Baza’s fit would be no tighter, with neighbors sixty degrees away on either side. In twenty minutes all the stress would be over; in twenty more he’d be sitting around a table joking with his colleagues about their long internment and the challenges of remote sex with distant partners as the light-speed lag grew longer.
The schematic began blinking, and a list of mismatches between the docking plan and real-time sensor readings began scrolling across the margin. Le’s voice came over the link. “We’re not holding! The magnets have – no, the magnets are holding. The cable’s come free, and there’s rock with it. We’ve torn off a piece of the asteroid.”
Heng switched to a radar image of the Tragopan falling away from Alcatraz, a four-hundred-meter length of cable twirling lopsidedly around it. He couldn’t tell if the cable had swiped the Curlew on its way into the void, but Doppler annotations on the image warned that all the remaining spokes were now swaying dangerously, pendulums set quivering by this seismic disruption.
Shen spoke from the Curlew. “We’re all right here. Swinging like a chandelier, but nothing’s broken. Xun?”
“The Stone’s maintaining pressure,” she replied. “One airlock is gone, but the bulkheads have sealed the breach. Le, what’s your status?”
“Shutting down the magnets,” Le replied tersely. Though both ship and cable were in free fall, the combined system had been rotating; severing the link would fling them apart, with no guarantee of a clean separation. Heng stared at the radar for a few tense seconds as Le fired his ion thrusters and managed to maneuver the Tragopan out of harm’s way.
Heng’s attention snapped back to his own problems. The pair of cables that the Baza had been meant to grab were oscillating back and forth, and though the radar could track this motion and the navigator could model its gradual damping, the uncertainties were so great that if the ship tried to dock now there was no guarantee of completing the process safely. Heng absorbed the numbers and then issued the command himself before the navigator intervened and made the decision for him. “Abort docking,” he subvocalised.
He waited for confirmation that they were steering clear of Alcatraz, then he banished the overlay and pulled himself out of his harness. “We’ve had a change of plan,” he announced. “We’ll be docking at the next Stone instead.” The passengers had trained for this scenario in Shanghai, so they all knew exactly what it would entail.
“Why?” Darpana demanded. “You said we’d be with everyone else!”
“The cables have developed a problem.” Heng saw a flag in his peripheral vision; Darpana was requesting a passenger-to-passenger link with the Tragopan. He refused it. “We have two hours, so you can de-suit for a bit if you want to.”
Rohini was looking worried, but she turned to her granddaughter. “Will you help me get out of this suit so I can wash? I want to feel fresh before I’m stuck in it again for who knows how long.”
Once Rohini and Darpana were in the ablutions room, Iqbal approached Heng. “What happened, exactly?”
“The Tragopan broke its mooring.”
“Was anyone hurt?”
“No.”
“So how do they get back to the Stone?” Akhila asked.
“They still have their ion thrusters.” Heng couldn’t meet her gaze.
“But that will take forever,” she said.
“It will take days,” Heng replied. “They’ll get back, but it’s going to take days.”
#
Heng tried to push the fate of the Tragopan out of his mind and focus on his own responsibilities. The passengers had been assigned partners to check each other’s suits, but he followed up with checks of his own. The suits were meant to be able to monitor their own integrity, but then, so were the Stones, and if the smallest leak could be perilous in a normal disembarkation, the harsher version they were about to attempt could turn any flaw into a fatality.
As they took their places in the bunks, he could see the grief in Rohini’s posture and the c
onfusion and resentment in Darpana’s. Rohini had told Heng that she’d explain everything to her granddaughter once they were out of the Baza; until then, the other passengers were doing their best to conceal their own distress.
Heng caught sight of the fallback Stone, approaching at three times the usual speed. It was like being strapped to a bullet that had been aimed at the edge of a throwing star. The Baza was on a trajectory that would pass between the cables almost at their tips, so there was no margin for error: if they were half a meter further from their target than intended, the magnets would get no purchase and they’d pass on by, as doomed as the Tragopan. He watched an overlay of the navigator iteratively refining its model of the encounter as better radar measurements came in, and the ghostly blue error cone around the trajectory grew ever narrower. But the error that would kill them would be invisible: an undetected crack deep in the machinery that would announce itself only at the instant it became impossible to rectify.
The Stone’s core shot out of view from the window beside the bunks, and the sun-side window on the adjoining wall was too heavily tinted to reveal anything meaningful. Heng held his breath and desperately willed his body to be crushed.
The four and a half gees slammed him down instantly: as the magnets grazed the cables’ extremities they’d had no chance to ease the ship smoothly up to the full centrifugal weight. The Tragopan had torn free at a third of this load; what right did he have to expect the Baza to hold?
But it did.
Heng lay pinned to his couch, his ribs burning with the effort of each breath, the cabin turning around him. Gradually the ion thrusters killed the spin; the room stopped moving, and there was a satisfying thud as the docking magnets gripped the cables at two more points, doubling the strength of the Baza’s hold.
There was nothing to do now but wait for the Stone to invite them in. Heng’s status overlay showed the cradle inching its way down from the rock toward the ship. Strange bright points streaked across his vision, but he couldn’t tell if it was his contacts or his retinas that were hallucinating fireworks under the strain. He wondered what kind of light show they’d see on the Tragopan, when solar protons boosted by the CME shock wave crashed through their vitreous humor and into their brains.
Heng felt his suit puff out around his forearms, the air it contained no longer opposed by the cabin’s pressure. The Baza’s hatch slid open, admitting a silver light reflected from the rock above that cycled between full-moon brightness and pitch black three times a minute. According to the overlay, the cradle was almost in place. Heng was half tempted to send Darpana up first, to spare the girl any more time under the punishing gravity, but the protocols were clear: if anything was amiss up on the asteroid it couldn’t be a passenger dealing with it, let alone a child. The captain had to be the first to leave the ship, however unchivalrous that seemed.
A chime sounded in his cans, and he focused on the flashing message in his overlay. The cradle was touching the Baza’s hull, but it was misaligned by a few centimeters, stopping it from passing through the hatch. The fucking thing had an air jet to deal with that kind of problem; what did the Stone expect him to do? Not even Akhila could have climbed up and helped the cradle through the entrance. Heng squinted at the image his contacts were painting until the final line of text became clear. The air jet had been tried but it wasn’t working; either the nozzle was blocked or a control wire had been severed.
“Navigator,” he subvocalised. “Compute the thrust to reposition us ten centimeters along the y axis.” They were hanging from the asteroid like a dead weight on a string, but they ought to be able to shift the equilibrium.
The force required was within the thrusters’ capacity. Heng had it build up as slowly as he could bear, giving time for the cables to dissipate energy so he wouldn’t set the Baza swinging.
After ten minutes, the cradle dropped down into the cabin and the winch positioned it next to Heng’s bunk. His harness disconnected from the couch beneath him; the cradle locked onto it at the side and slid him over into the suspended sling.
He rode up in airless silence, unable to turn his gaze to the side to look across at the stars. All he could see was the rock straight above him, cycling through its ten-second days and nights: a lighthouse, a prison, a safe port for all the loneliness and grief to come.
#
“Will you talk to her?” Rohini pleaded. “She trusts you.”
“Trusts me?” Heng was confused. “She can’t believe you’d lie about something like this.” He could hear Darpana’s wailing, rising and falling like a song.
“Not deliberately,” Rohini replied. “But you’re the expert. If you explain to her why there’s nothing we can do, she’ll believe you. When I tell her the same, she just screams that I don’t know what I’m talking about.”
Heng gathered his courage and strode down the corridor. The child had brought joy and innocence to the Baza, but now it was his duty to help her understand her cousin’s fate.
He knocked on the door of Darpana’s cabin. She stopped her keening and he heard her spring up off the bed. When she slid the door open she did not look surprised; Rohini must have promised to send him to talk to her.
“Why aren’t we rescuing them?” she demanded. “Why aren’t we going after them?”
“If we met up with them, how would that help?” Heng asked gently. “Our thrusters are no stronger than theirs.”
Darpana stared at him contemptuously. “We don’t just have our thrusters!” she replied. “We have this whole Stone! We can throw the Baza in any direction at a hundred and fifty meters per second!”
“Yes,” Heng agreed. “So we could reach the Tragopan quickly, but what good is that if we can’t match its speed? And if we did match its speed, we’d all be in the same boat.”
Darpana said, “We don’t match speed with the Stones, do we?”
Heng rubbed his eyes; he was still giddy from all the changes in weight. “We do, though: we match speed with the cables.” She knew that perfectly well, but he couldn’t blame her for saying or thinking anything as she sought some miraculous reprieve. Heng had met Lomash briefly before the convoy set out from orbit, but now he tried to wipe the boy’s smiling face from his mind. Le would haunt him; that was hard enough.
“So we take some cable with us!” Darpana retorted. “And spin it as fast as we have to!”
Heng stood with his arm resting on the door frame, squinting to try to see past the defects swimming through his eyeballs. Taking cable with them would have sounded like nonsense a day ago, conjuring up an image of him packing a reel of it in the cabin and then trying to deploy it as the rendezvous approached. But the Tragopan had certainly taken cable with it when it ripped a whole double strand loose from Alcatraz.
If they could find a safer way to mimic that feat, could they turn the Baza itself into a kind of impromptu Stepping Stone? The ship wouldn’t need to be crewed; it would merely have to cross paths with the Tragopan, carrying enough speed and spin for the Tragopan to effect the necessary U-turn and get back to Alcatraz. One of the four docked ships could be sent between the Stones to replace the Baza.
“Let me think,” he told Darpana. He turned and walked away.
Heng contacted Liana first, privately. He did not want to give Le and the others false hope if the scheme proved impossible from the start.
“You don’t have the tools to slice through nanotube cables,” Liana declared bluntly.
“Are you certain?” Heng wished he’d queried the inventory first, but if the company didn’t want him to have the means to hack a spoke off the Stone, the computer would have lied to him anyway. “If this isn’t the emergency that justifies some serious vandalism, what is?”
“It’s not about damaging property,” Liana replied. “Your responsibility is to your own passengers. If you breach the integrity of your living space, you’ll just kill nine more people.”
“You’re right.” Heng cut the link; he was wasting his time with
her. The legal position would be crystal clear: the company could not endorse his plan, let alone facilitate it. And he had no right to endanger the Baza’s passengers without their consent.
Heng gathered everyone in the conference room, Darpana included, and explained precisely what he wanted to do.
“We don’t have much time to make a decision,” he said. “If this goes wrong, it might damage the Stone badly enough to kill us. Or we might spring a leak and lose pressure, so we’d have to live in suits until we can make repairs.”
“Or we might get away with it unharmed,” Punita suggested.
“We might,” Heng agreed. Alcatraz had survived its own amputation. “But don’t ask me for the odds.”
He passed a sheet of paper around the table, with two columns to record the votes. Everyone would have the power of veto; he couldn’t let a mere majority coerce anyone into risking their life.
As Chandrakant accepted the ballot he looked up at Heng with an expression of pure loathing. Heng shifted his gaze and stared at the far wall; he’d done nothing deliberately to alienate the man, but it was too late now to try to placate him.
Iqbal touched Heng’s shoulder; the paper had only taken thirty seconds to come full circle. Heng accepted it and unfolded all the creases that people had made to hide their votes from the next recipient.
There were nine marks in the YES column.
#
Heng organized the passengers into work teams, fetching trolley-loads of rubble from a cul-de-sac that the tunneling machines hadn’t fully cleaned out. Each courier weighed their contribution on a set of bathroom scales, and Darpana had the job of double-checking the readings and the running total.
The company had had the Stone’s automation disable the motorized winch for the cradle, so Heng and Akhila took turns operating it by hand. A purely mechanical regulator prevented it from unwinding uncontrollably, even as the weight it was bearing quadrupled, and Heng had offset the rope so that the combined centrifugal and Coriolis forces saw it drop squarely into the hatch below. The real effort went into hauling the empty cradle up again.