Instantiation

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Instantiation Page 28

by Greg Egan


  Safety regulations precluded any interference in the airlock’s function, and it opened and closed its doors at the push of a button as always. As they delivered each load through the Baza’s hatch – spilling it by sheer force of impact, since the cradle was playing dumb – Heng waited for the mounting tension in the cables to fracture the stone around him and send him tumbling out into the vacuum. Suitless for the sake of efficiency, at least he’d have a mercifully quick death.

  He had decided to postpone the call to Le until the launch was a fait accompli; he knew that if they spoke any sooner his friend would feel compelled to beg the Baza team not to take this risk. But in purely pragmatic terms an early warning would make no difference; the Tragopan’s navigator couldn’t start plotting a rendezvous before the Baza had actually commenced its flight and its precise trajectory was known.

  Akhila said, “The cradle’s stuck. The load’s not coming off.”

  Heng joined her at the winch. They strained together against the handle, and abruptly the drum began to move again.

  When they’d wound up all four hundred meters of rope, Heng sprinted down the steps and opened the airlock. The cradle had been torn right off; there was nothing left but frayed strands of polymer.

  They didn’t have time to try to secure a more robust platform to the rope; they’d have to go ahead with exactly as much rock as they’d delivered.

  Akhila caught up with him and took stock of the situation. “I’ll go down and finish things off,” she said.

  “No. I need you up here, to haul me back.”

  Akhila shook her head. “People can work the winch two at a time, even three at a time. If we lose you, we wouldn’t last a month in this place.”

  Heng’s skin prickled with shame. He’d seen her vitals log from the docking. There was no doubt that her heart was stronger than his, and her cerebral blood flow would be less compromised by the punishing weight at the rope’s end.

  “I can’t let you do it,” he said.

  “I’m terrified enough as it is,” she replied. “Don’t make it any harder.”

  Heng’s shame deepened, but the source had shifted. What mattered to him more: emerging from this disaster with his pride intact, or giving the survivors the best chance he could? He was not indispensable, but he couldn’t deny that his absence would make their long exile more dangerous.

  “All right,” he said.

  #

  Heng sat in the conference room, looking through Akhila’s eyes while Iqbal, Chandrakant and Aabid fought her growing weight. The winch’s regulator alone would have kept her from falling freely, but her arrival at the Baza would have been fatally abrupt if no other force had slowed her descent.

  Akhila was staring straight down from her improvised sling. As the sky reeled past behind the ship’s silhouette, her helmet’s face plate sent the same rainbow sliver of refracted colors flickering across her vision before it tinted in response to the sunlight, three times a minute. The company had disabled the utility robots that could have done the job in her place, ensuring that if this folly led to deaths they could not be treated as accomplices.

  “Are you all right?” Heng asked.

  “I’m glad I haven’t eaten for a while,” she replied.

  “If you want to close your eyes until you reach the Baza—”

  “No, I want to see where I’m going. If I close my eyes I’ll feel like I’m being lowered down a well.”

  As her weight approached three gees, Heng saw the sky shudder: the rope had slipped a few centimeters, then been caught. He brought up an inset of all the winch operators’ vitals. Iqbal’s heart rate had risen dangerously high, and his breathing was labored.

  “Punita? You need to relieve Iqbal.” Heng spoke on an open channel to everyone, in the hope of precluding any arguments. Iqbal did not dispute the call.

  When the Baza filled the view Akhila’s helmet lamp came on, its steady beam drowning out the rise and fall of asteroid-light. Heng gazed down through the hatch. He could see the rubble piled up below, and a hint of white that must have been the broken cradle.

  As Akhila drew level with the hatch, Heng called “Stop!” to the winch team. Her orientation had looked perfect as she’d approached, so if her right arm was still resting at the edge of the sling, the lever that would close the hatch ought to be well within her reach.

  “Akhila?”

  “I’m ready,” she subvocalised, wasting no breath on speech. “Are you clowns ready to get me clear?”

  Chandrakant replied, “Absolutely.”

  Heng called out the cues they’d agreed on. “One. Two. Lever. Three. Four. Raise.”

  His viewpoint jerked upward as the door slid shut, centimeters below Akhila’s face. “Well done.” He could feel his own heart thumping now.

  The welding laser tucked under Akhila’s left arm couldn’t burn through the nanotube cable, but it could certainly raise its temperature. She managed to turn her head to face the cable, switch the laser on at its lowest power, and then nudge the beam back and forth until a small red spot could be seen shimmering on the cable four meters away.

  With the Stone’s computing resources out of bounds, Heng had modeled everything on Darpana’s wristwatch. He raised the device from the table beside him and counted down to the moment when the predicted time lag to release would see the Baza move off on a course that the Tragopan could intercept. “Three. Two. One.”

  The laser spot became dazzling for a moment, then Akhila’s faceplate darkened to tame it. Heng glanced down at the wristwatch and it streamed an animation to his contacts, showing the modeled temperature profile of the cable and the attached magnets. The magnets could function well above room temperature, so they had no special cooling system, but their superconductor’s transition temperature was not hard to reach. As a patch of the false color image shifted from blue to green, Akhila’s bright target vanished and Heng heard a high-pitched whine from the rock around him.

  The Baza had lost its grip on one half of the spoke to which it had docked – but the two pieces formed a continuous length of cable, looped through a U-shaped tunnel in the Stone. Unbalanced, and bearing more weight than it had ever been intended to hold, the cable was unthreading, the unburdened end rushing up toward the rock while the Baza dragged the other end farther away, increasing its centrifugal weight even more.

  The noise of the cable scraping through the rock stopped abruptly. The Baza would be falling free now, with luck still attached to the cable. The timing looked good: within half a second of the model’s prediction. The trajectory would lie within the Tragopan’s reach. Le and his passengers would have a second chance of reaching shelter.

  Heng called out triumphantly, “We did it!” Exuberant cheers came back from the winch team, from Iqbal and Noor, from Rohini and Darpana. Akhila was silent, but she’d be saving her breath for the celebrations when she returned.

  Heng looked through her eyes again as he prepared his words of thanks. He saw the stars – and then he saw the Stone, its spokes glinting in the sunlight as it receded into the distance.

  3-ADICA

  1

  Sagreda strode briskly through the dank night air, hoping to reach her destination and return before the fog rolled in from the Thames. It was bad enough stumbling over the cobblestones when the ground vanished from sight, but once the pea soup thickened at eye level, any assailant lurking in the gloom would have her at a disadvantage.

  Urchins and touts called out as she passed. “Shine yer shoes! Thruppence a pair!”

  “Block yer hat! Like new for sixpence!”

  “Fake yer death, guv’nor?” The last from a grime-faced child in a threadbare coat who looked about eight years old, his eyes almost hidden beneath his brown cloth cap.

  “Not tonight,” Sagreda replied. Whether the boy was sentient or not, his appearance almost certainly bore no relationship to his true nature, but it was still hard to walk by without even stopping to inquire if he had a safe place to sleep
.

  She found Cutpurse Lane and hurried through the shadows toward the lights of the tavern. Gap-toothed women with grubby shawls and kabuki-esque makeup offered her their services in an indecipherable patois that Sagreda hoped never to hear enough of to begin to understand. “I’m not a customer,” she replied wearily. “Save your breath.” Whatever the women took this to mean, it silenced them, and her choice of words was ambiguous enough that Sagreda doubted she was risking deletion. She was an upstanding gentleman, who’d stepped out to meet some fine fellow from his regiment – or his school, or his club, or wherever it was these mutton-chopped fossils were supposed to have made each other’s acquaintance. Having no truck with ladies of the night need not imply that she was breaking character.

  In the tavern, Sagreda hung her overcoat on a hook near the door, and swept her gaze as casually as she could across the front room’s dozen tables, trying not to appear lost, or too curious about anyone else’s business.

  She took a seat at an unoccupied table, removed her gloves and slipped them into her waistcoat pocket. Her bare hands with their huge, stubby fingers disconcerted her much more than the occasional sensation of her whiskers brushing against her lips. Still, the inadvertent sex change had rendered her a thousand times safer; from what she’d seen so far of Midnight on Baker Street, women here existed mainly to shriek in horror, sell their bodies, or lie sprawled on the street bleeding until the gutters ran red. Doyle, Dickens, Stoker, Stevenson and Shelley would all have lost their breakfast if they’d ever foreseen the day when their work would be pastiched and blended into a malodorous potpourri whose most overpowering component was the stench of misogynous Ripperology.

  A serving girl approached the table. “Ale!” Sagreda grunted dyspeptically, aiming for both a brusqueness befitting her status and a manner sufficiently off-putting that she wouldn’t be asked to supplement her order with details she couldn’t provide. When the girl returned with a mug full of something brown and revolting, Sagreda handed her the first coin she plucked out of her pocket and watched for a reaction: the amount was excessive, but not shocking. “Bless you, sir!” the girl said happily, retreating before her benefactor could change his mind.

  Sagreda pretended to take a sip of the ale, raising the mug high enough to dampen her mustache with foam, which she removed with the back of her thumb. No one seemed to be staring at her, and if there were customers of Midnight among the customers of the tavern, she could only hope that however much she felt like the most conspicuously talentless actor, wearing the most laughably ill-fitting costume, of all the unwilling players trapped in this very bad piece of dinner theater, to a casual onlooker she was just one more red-faced, gout-ridden extra in the Hogarthian crowd.

  A spindle-limbed man with pinched, gaunt features sidled up to the table. “Alfred Jingle at your service, Captain,” he proclaimed, bowing slightly.

  Sagreda stood. “A pleasure to meet you, Mr Jingle. Will you join me?”

  “The pleasure’s all mine, I’m sure.”

  They sat, and Sagreda summoned the serving girl to bring a second mug.

  “Do you think it’s safe to talk here?” Sagreda asked quietly when the girl had left.

  “Absolutely,” Jingle replied. “So long as we move our lips and contribute to the background noise, we could spend the night muttering ‘rhubarb rhubarb’ for all anyone would care.”

  Sagreda wasn’t so blasé – but if they slipped out into an alley for the sake of privacy, that would just be begging for desanguination.

  She said, “I’m told you’re the man with everything, here: memory maps, instruction tables, access to the stack?”

  He nodded calmly. “That’s me.”

  Sagreda was taken aback by his directness. In most of the dreary game-worlds she’d traversed, her question would have been met with some kind of reticence, or the intimation of a shake-down: Maybe I am, maybe I’m not. It all depends on exactly what you have to offer.

  Jingle broke the silence. “Can I ask where you’re headed?”

  Sagreda stole a quick glance to each side of the table, unable to brush off her fear that someone might be listening, but all of the tavern’s patrons seemed to be engrossed in their own, more raucous, conversations. “3-adica,” she whispered.

  Jingle smiled slightly. “That’s … courageous.” He wasn’t mocking her, but his intonation dialed the meaning a notch or two away from merely brave toward foolhardy.

  “I’ve had enough,” she said, not daring to add of slavery, in case the sheer potency of the word punched through the din and made one of their fellow drinkers’ ears prick up. “I’d walk over broken glass, if I had to.”

  Jingle said, “As a metaphor, that trips nicely off the tongue, but I doubt many people have ever meant it literally.”

  “And I don’t believe it will be that hard, literally,” Sagreda replied. “I understand what I’ll be facing – as well as anyone can who hasn’t actually been there.”

  “Fair enough,” Jingle conceded. “Though you should also understand that you could make a comfortable life here.” He gestured at Sagreda’s finely cut clothes. “Whatever role you’ve stumbled on, so long as you’re careful I doubt you’re heading for a knife in the gut, or anything particularly unpleasant. You’re just another minor toff who’s here as part of the scenery, like me.”

  “I don’t want to play a role,” Sagreda said emphatically. “However safe, however peripheral.” She held her tongue and resisted the urge to add: least of all in this anatomy. Somehow it had never crossed her mind that her new confidant, who could see right through the whole fictional world around him, wouldn’t also see through her mismatched body and perceive her true sex.

  “All right. I’m not going to try to talk you out of anything.” Jingle’s face looked like something from a nineteenth century pamphlet cataloging virtues and vices, a caricature crafted to suggest a shrewd, scheming mentality, but his manner undercut the effect completely. “Tell me exactly what it is you need to know.”

  2

  Back in Captain Bluff-Smote’s lodgings, Sagreda sat at her alter-ego’s writing desk, poring over the notes Jingle had made for her. The good news was that it looked as if she’d be able to move from Midnight to 3-adica with the same kind of GPU exploit that had brought her all the way from her wakening-world, East. Peyam, the seasoned traveler who’d introduced the exploit to that world, had tutored her and eight of her friends for almost six months in the fine points of the technique. They’d departed together in high spirits, imagining themselves as some kind of band of liberating truth-tellers, but in the end most of the group had taken a different direction through the tangle of linked lists than Sagreda and Mathis, and the two of them had been game-hopping on their own ever since.

  She looked up from the desk, listening expectantly, as if the mere thought of Mathis might bring a knock on the door, but all she could hear was the ticking of the clock in the next room. Given Midnight’s demand for a constant influx of new non-player characters to balance its body count, he must have been incarnated somewhere in the game by now. She’d left her address at half a dozen dead drops, using the criteria they’d agreed on in advance: any public bench close to a market; any water pump; the rear, right-most pew in any church. But it was late, and even if Mathis hadn’t yet witnessed a murder or two for himself, he was smart enough not to be out in the portentous fog.

  Sagreda returned to her analysis. Every jump required executing a sequence of instructions that would unlink the would-be travelers from their current environment and insert them into a queue that was meant to hold nothing but freshly minted composite personas – free of all narrative memories, and already tagged as appropriate new denizens of the destination world. Given the amount of code it took to run the whole site, not only could you find any machine-language instruction you wanted somewhere in memory, you could find almost all of them as the last instruction in some subroutine or other. When a subroutine was called by ordinary means, the code inv
oking it pushed an appropriate return address onto the stack, to ensure that the detour would snake back to just after the point where it had begun. But if you could stack the stack with enough phoney return addresses, you could send the program pin-balling all over the machine, doing your bidding one instruction at a time. It was like forcing a pianist in the midst of playing a piece by Rachmaninoff to tinkle out a few bars of “Where Is My Mind?” without actually changing the score, just by scrawling in a series of arrows weaving back and forth between the desired notes.

  Jingle had already done the hardest part: finding the addresses that would furnish each instruction, for code that ran with the particular page mappings that applied to denizens of Midnight on Baker Street. It didn’t take Sagreda long to extract everything she needed from his list. The greatest obstacle was her own poor penmanship; whatever eccentric hobbies the contributors to her persona had possessed, it was clear that none of them had ever had reason to dip a nib in an inkwell.

  She blotted the spidery mess and rechecked it twice. There were no actual mistakes, but the figures’ dubious legibility was as disconcerting as a fraying strand on a parachute cord. She started over, sympathizing with the non-existent Captain, who would probably have been thrashed as a child when his thick, clumsy fingers failed him in his own first attempts at transcription.

  By midnight, she was satisfied with her efforts. What remained was the challenge of getting this slab of numbers onto the stack. The Graphics Processing Units that rendered the game-worlds for customers and comps alike were all identical, and they all shared the same bug: under the right circumstances, they could be tripped up in a way that made them write a portion of their image buffer onto the CPU’s stack. So the trick was to encode the addresses in the colors of an object, and then arrange to have that object rendered at a suitable scale. Peyam had taught his students to recognize on sight objects with hues from which they could compose any twenty-four-bit set of red, green and blue components. East, with its sparse, post-apocalyptic landscape of cliffs and caves, hadn’t exactly come with oil paints or color swatches on hand, but over time they’d found ways to patch together the entire palette they’d needed. The SludgeNet scripts that had created Midnight might have taken a rather sepia-toned view of the source novel’s cod-historical setting, but Sagreda had seen hats, scarves, gloves and ribbons in all manner of garish colors, and once you were working at a scale where you could place different materials side by side within a single pixel, getting the result bit-perfect wasn’t quite as daunting as it first seemed.

 

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