The Eternal Flame

24

Carla helped Ivo attach his spectrograph to the telescope, then watched him load the first sample into the catapult beside the window: the first small irritant with which they hoped to goad the Object into a revelatory response. The Gnat had no airlock as such—nothing large enough for the crew to come and go without depressurising the whole cabin—but Marzio had designed a miniature version, equipped with lever-operated scoops and pincers, that allowed them to move these tiny samples the short distance through the hull and into the catapult’s launch tube.

Back when the surface of the Peerless had been suffering the sporadic flashes attributed to orthogonal dust, no one had ever managed to observe—let alone record—the light’s spectrum. Before the centrifugal force of the mountain’s spin put an end to those displays, people had proposed spectrographs with such a wide angle of view that the inability to know precisely where the light would be coming from would cease to matter. The problem they’d never solved, though, had been the question of timing: no one could react quickly enough to open a shutter just as the flash occurred, and a prolonged wide angle exposure, even if it encompassed one of the rare events, would bury any signal from the flash itself in the accumulated background of reflected starlight.

No one had managed to find so much as a single tiny crater or other blemish left behind by the strange ignitions. With no more empirical clues, three generations of travelers had been left to speculate about the collisions. That the modest spin of the Peerless had been enough to brush the encroaching specks of dust aside ruled out sheer speed of impact as an explanation for the flashes, in favor of some kind of chemical reaction with the rock of the mountain itself. But no theory of chemical luminescence, no theory of fuels and liberators, no theory of light and luxagens, had ever offered a believable account of the events.

Ivo said, “One scrag of calmstone, delivered to the northern gray flats.”

He released the catapult.

Carla glanced across the cabin at Ada, who was resting a hand on the emergency lever that would fire the engines immediately to propel the Gnat out of harm’s way if the Object did a Gemma and began to transform itself into a star. Tamara, clinging to the rope beside Ada, was wearing a heavy blindfold. If the Object burned so fiercely that its radiance became injurious, this macabre precaution might at least spare the sight of one of their navigators.

Carla bent down and peered through the theodolite in front of her—willingly putting one eye at risk in order to cover the opposite contingency, that the flash might be too weak to see any other way—while her fingertips brushed the dials of the adjacent clock. They believed they knew how long it would take the speck of calmstone to reach the surface, but if the reaction itself was delayed the exact timing would be a valuable further datum.

“Opening the shutter,” Ivo said softly.

Carla stared at the starlit gray surface, expecting an anticlimax. The secret that had eluded generations couldn’t give itself up with the first grain of sand they tossed. She felt the dials reach the estimated impact time and move on: one pause beyond, two, three—

A dazzling point of light blossomed against the grayness, like a sunstone lamp seen through a pin-hole. Carla dutifully transcribed the precise time of the event onto her thigh even as she waited for the pin-hole to burst open, for the barrier between the realms to be torn apart and chaos to come spilling through.

The light faded and died. Carla quickly turned around and put an undazzled rear eye to the theodolite. There was no wildfire spreading from the impact site. The surface appeared completely unchanged.

Ivo said, “Tell me I didn’t hallucinate that.”

“Hallucinate what?” Tamara asked impatiently.

“It was bright but… contained,” Carla managed. “Just as they described it in the old fire-watch reports!” Just as Yalda herself had first seen it—looking back on the Peerless from the void, when a construction accident during the building of the spin engines had almost sent her to her death.

Ivo pulled the strip of paper out of the spectrograph. Carla lit a lamp so they could examine it properly. The paper had been darkened across the entire range of frequencies, showing a spectrum similar to that of the light from any burning fuel. But superimposed on this was a feature so sharp that Carla at first mistook it for a calibration mark on the paper—a line Ivo might have drawn for the purpose of alignment. It was no such thing. The paper had been blackened by the flash itself, along a narrow band corresponding to an ultraviolet wavelength of one gross, eight dozen and two piccolo-scants.

Tamara was keeping her blindfold on, so Carla explained the results to her.

“What could produce that?” Tamara asked. “A single, sharp ultraviolet line?”

“I’ve never seen anything like it,” Ivo declared. “No ordinary rock burns with a narrow peak brighter than all the other light from the flame.”

“Let alone just one peak,” Carla added. “The total amount of energy a luxagen needs to gain in order to escape from calmstone would be something like two dozen times greater than the jump corresponding to that ultraviolet line. You’d expect a liberator for calmstone to modify the energy levels so the total gap was bridged in a lot of small steps—but there’s no reason why all of those steps should turn out to be identical in height!”

Ada said, “And yet, there it is: one lonely peak.”

Ivo launched a second scrag of calmstone, this time at the red-tinged portion of the Object’s southern lobe. The terrain here looked as if it was covered in firestone; watching through the theodolite, Carla braced herself for the sight of a wildfire, if not a full-blown Gemma event.

Three pauses and five flickers after the impact, there was a single, brief pinprick of radiance.

When Ivo extracted the paper from the spectrograph, there were some minor differences across the visible frequencies but the spectrum was dominated by exactly the same ultraviolet peak as before.

Ivo repeated the experiment, choosing two more regions of the Object with their own distinctive appearance. Then he switched the projectile from calmstone to hardstone, then powderstone, clearstone, mirrorstone, firestone and sunstone. In two dozen and four variations, the delay before the flash was sometimes a little longer or shorter, and the visible part of the spectrum showed clear differences that depended on the particular area being targeted on the surface. But in every case, a single ultraviolet line blackened the paper at exactly the same position.

Carla could offer no explanation, and Ivo was equally perplexed. Ivo went so far as to aim the spectrograph at a lamp inside the cabin, to see if the ubiquitous line was really just the product of some bizarre flaw in the optics. It wasn’t.

“Take away the ultraviolet line from this spectrum,” he said, holding up a strip of paper he’d exposed to a flash from the red rock of the southern lobe, “and take away the liberator lines from this one.” He grabbed the test strip he’d made from the lamp. “Apart from those features, they both look the same: burning firestone.”

“So firestone is firestone, luxagen-swapped or not,” Ada said. “Once it’s actually burning, the light is identical, just as Nereo’s theory would predict.”

Carla said, “But the process by which the Object’s firestone is being set alight looks nothing like the way a liberator acts on ordinary firestone. And it’s completely indiscriminate: it acts the same way with every mineral. It doesn’t care about the detailed structure of any of these solids—their geometry, their energy levels. It just does its magic trick and pfft…”

Tamara finally took off her blindfold. “Whether or not we understand the ignition process, surely this is an answer to the fuel problem? Every scrag of the Object can be made to burn! A little too easily for comfort… but if we can slow this thing down enough to keep it in reach, the next generation can deal with the practicalities.”

“Or the next generation could catch up with it and fetch it back,” Ada suggested. “They’ll have had time to think deeply about the results we’ve seen, and work out what’s really going on. We know the Object’s trajectory with very high precision now. We can’t lose track of it.”

Tamara almost seemed swayed, but then Ivo interjected angrily, “We came here to capture the Object! That was the mission the Council approved: to take samples, to do calorimetry, then to trigger a blast that would leave this thing motionless. If we give up now, all we’ll be bequeathing our descendants is a longer journey and a more difficult version of the task we should have done ourselves. We’ve had three generations of theorizing about orthogonal dust, and that’s left us none the wiser. The only way to understand this material is by experiment.”

Ada said, “You’ve just completed a whole set of experiments! Do you really want to get any closer to something that can set every tool and container you have on fire?”

“I have the air tools,” Ivo insisted.

“Which can only carve powderstone,” Ada replied.

Ivo rummaged through the spectra, then pulled out one strip. “Here! The gray mineral, in the north. As you said, luxagen-swapped or not, the basic properties of a substance are the same. Except for the ultraviolet line, this spectrum is the spectrum of powderstone! To the eye, this rock looks like powderstone! Physically, there is no reason why it shouldn’t be every bit as soft as powderstone.”

Ada and Tamara looked to Carla. “I can’t argue with that,” she said. “It ought to have the same mechanical properties as the ordinary mineral. But from what we’ve just seen, if a speck of it touches anything—”

Ivo said, “There’ll be air flowing out of my cooling bag, constantly. The Mite has an air shield around it too. I’ve practiced this: I know I can take a sample of powderstone without touching it.”

Tamara was silent for a while. “All right,” she said reluctantly. “If you’re still confident that you can do this, I’m not going to stand in your way.”

She reeled in one of the guide ropes to make some room, then Carla helped Ivo slide the Mite out of its storage bay and bring it to the middle of the cabin. It was less a vehicle in its own right than a kind of chemistry workbench fitted out for the void, with air jets attached. As Ivo’s understudy, Carla had had her own rehearsals with a mock-up of the thing, maneuvering it around the Peerless and practicing the descent from orbit. After a few days she’d become quite comfortable with the way it moved—but she’d lost count of the number of gentle collisions she’d had with the mountain.

She moved aside to let Ivo run through his equipment checks. Ada watched the process with an expression of contained disapproval, though Carla suspected that what she most resented was Tamara ignoring her advice. Ada had prepared herself to lead the mission, to bear the final responsibility for everything they did. However much she’d rejoiced to learn that her friend was alive after all, it must have been difficult to relinquish that commanding role.

Tamara told Ivo, “I want you to limit yourself to the powderstone outcrop. Trying to get samples anywhere else will be too difficult; that one mineral will have to serve as a surrogate for all of them.”

“I can live with that,” he replied. He was testing the recoil balance for his air blades, hovering beside one of the remaining guide ropes, proving that he could maintain a fixed separation from it even as he waved the invisible cutting jets about. “Whatever’s responsible for that ultraviolet line looks like the strongest reaction in every case. So if we can quantify the energy release for powderstone—”

Ada said, “What’s wrong with your right arm?”

“Nothing.” Ivo shut off the cutting jets and held up the accused arm for inspection. “Why would you even—?”

“You’re favoring the left one,” Ada said flatly.

“That’s not true,” he protested. “This is a whole new limb! Since I re-extruded it there’s been no pain at all.”

Tamara said, “Hold onto the rope and give the Mite some spin around a vertical axis, using your right hand.”

Ivo buzzed, offended. “Why would I ever need to do that? If I need to adjust the orientation, that’s what the air jets are for.”

“I know,” Tamara said quietly. “I just want to see how strong that arm is.”

Ivo gripped the rope beside him as she’d asked, and reached for the edge of the Mite with his right hand. He managed to get it spinning, but his struggle to ignore the pain was obvious now.

Carla understood: the flesh from his battered right arm hadn’t recovered, because he hadn’t actually managed to resorb it. He had gone through the motions of drawing it into his torso and making it appear that he was extruding an entirely new limb, but the injury had kept the damaged tissue stuck at its original site.

Ada said, “You can’t go out there with an injury.”

Caught out in his deception, Ivo had no reply. Carla couldn’t help feeling some relief that he had been spared the risk of the excursion—but Ada seemed altogether too pleased with the outcome. Ada had had the chance to revel in her own skills, as no navigator had for generations; why should Ivo be cheated of the same kind of fulfillment? What satisfaction was there in tossing sand at the Object, watching the fireworks, then running away? He was a chemist, and he’d come here to do chemistry: he needed to get as close to dirtying his hands as possible, without actually going up in flames in the process.

Carla heard herself saying, “I’ll go with him. I’ll be his right hand.”

“There’s no provision for two operators in the mission plan,” Ada replied, as if that settled it.

“I know how to use the Mite,” Carla said, stubbornness winning out over fear. “If Ivo had had to stay behind for some reason, I’d be the one charged with doing his job. But with a mild injury like this… he’s got too much experience to be replaced. We can add a second harness to the Mite, go out together, and I’ll be there to back him up if he needs it.”

Ada turned to Tamara, scowling. “You can’t possibly countenance this!”

Tamara said, “Ivo?”

“We can make it work,” he said, glancing at Carla with an expression of newfound respect. “I’m sure we can.”

“Let’s just try some rehearsals first,” Tamara said cautiously. “Each of you operating the Mite up here in orbit, with the other in harness as a passenger. If you strike any problems, the whole thing is off.”

“Of course,” Carla agreed. “That sounds fair.” She could feel her whole body growing charged with excitement, even as the voice of prudence in her head began howling in disbelief.

Ivo reached over and placed his palm against Carla’s, their skin making contact through the small apertures they’d cut into the cooling bags.

Ready? he wrote.

As I’ll ever be, Carla replied.

She glanced up at the Gnat, a dozen strides above them; Ada and Tamara were looking out through the window, their forms visible in the starlight but their faces impossible to read.

Carla rested the exposed fingertips of her lower right hand against the dials of the clock on the underside of the Mite, and wriggled a little to make herself more comfortable. She and Ivo were harnessed to a long flat plate that ran beside the main structure, held apart from it by six narrow struts. Struts and plate alike were hollow, and covered in fine holes; just as air flowed out through the fabric of her cooling bag, every part of the Mite was leaking, sending a thin breeze wafting out into the void in the hope of warding off danger. For all the sense this made, Carla still felt almost comically exposed—as if a solid hull like the Gnat’s might have offered them greater protection.

Ivo reached down and opened the valve on the air jet to his left. In itself, the kick of acceleration was barely noticeable; Carla merely felt as if one side of her harness had been drawn a little tighter. But when she looked up again the Gnat was receding—outpacing them in its orbit now, as the blast of air acted as a gentle brake on the Mite.

Ivo shut off the jet. They were separating from the Gnat so slowly that Carla could imagine Tamara stepping out through the hatch onto a fanciful sky-road, catching up with them effortlessly and handing them some item they’d neglected to pack. As for their rate of descent, that was too slight to discern at all. But the tiny reduction in their orbital velocity had reshaped their trajectory from a circle into an ellipse; in six bells, their altitude would be less by a factor of ten.

The whole flight plan they’d prepared relied on the assumption that the usual principles of celestial mechanics would keep working in the Object’s environs. Given the spectacular failure of traditional chemistry Carla wasn’t willing to take anything for granted, but all the evidence so far was that the orthogonal rock beneath them was producing the same kind of gravitational field as a comparable body made from ordinary matter. From the Gnat’s orbital period Tamara had estimated the Object’s total mass, and her figure was consistent with the kind of minerals Ivo’s spectra had identified on the surface. Rock couldn’t magically change into something entirely new just because you encountered it at a different angle in four-space. Indeed, one faction among the chemists maintained that ordinary matter ought to contain both positive and negative luxagens—in equal numbers, symmetrically arranged—and that the swapped rock in the Object would thus be literally identical to ordinary rock. Carla had had some sympathy for the notion on purely esthetic grounds—and it certainly would have made Silvano happy if it had turned out to be true—but the fate of Ivo’s projectiles had demolished that idea.

Comfortable? Ivo asked her.

She turned to him. Sure. Ivo looked composed, as far as she could judge from the sight of his face through his helmet. If all went well, for the next six bells they’d have nothing to do but watch the stars and the scenery. All the danger would be down on the surface—and the trick to staying sane until then was to accept that they couldn’t speed up their descent and get the whole thing over any sooner.

Carla gazed down at the gray plain directly below the Mite; though they were leaving this region behind, it was precisely where their spiral journey would finally deposit them. The craters here were wider and more numerous than elsewhere on the surface, bolstering the hope that the gray rock really would turn out to be as soft as powderstone.

As the plain slipped away she tried to imagine the collisions that had left these craters. The strange reaction with ordinary matter was probably not to blame; they looked too much like Pio’s craters, the product of nothing but like crashing into like at planetary speeds. The astronomers believed that the Object had started out deep within the orthogonal cluster a dozen light years away, then spent eons drifting alone through the void. Once, though, it must have been part of something larger.

What had torn that mother world apart? Perhaps a wildfire deep within it. A wildfire ignited how? By the tiny probability for every luxagen in every rock to break free from its energy valley—with the chance of escape mounting up over cosmic time. Some solids would be resilient, succumbing to nothing more than an inevitable slow corrosion, but others would suffer a kind of avalanche, with the change at one site shrinking the gaps between the energy levels for its neighbors, accelerating the process.

In the end, everything in the cosmos wanted to make light and blow itself to pieces. The only thing that differed was the time scale, set by the number of photons required to make the leap from solidity to chaos. But if the luxagens in most kinds of rock needed to make six or seven photons at a time in order to decay—six or seven far-infrared photons, each with the highest possible energy—what could possibly shrink that gap down to the single ultraviolet photon that Ivo’s spectra had revealed?

Carla’s gut tightened. She hadn’t been hungry since the journey began, but she found herself longing for the comforting aroma of groundnuts.

Other hands feeling steady? she asked Ivo.

Very, he assured her.

She wanted to see this reaction close up; the more she pondered the mystery, the more she ached to understand it. She just didn’t want to end up partaking in it herself.

Gyroscopes kept the Mite’s orientation locked against the stars, so as its orbit carried it around the Object, the Object in turn moved across the sky. Carla hardly needed to check the clock to know when they’d made half a revolution: the terrain that now stretched out above her head, its wide horizon upside down but level, rendered the whole configuration obvious.

It was her side of the Mite that was leading now, so it was her turn to brake the vehicle. She opened her air jet, counting the flickers beneath her fingertips, delivering a blast a little longer than Ivo’s. Their new orbit would be much rounder than the last one, but still sufficiently elliptical for its closest approach to bring them almost to the surface. Skimming above the powderstone plains, they could choose the most promising site and then kill their velocity entirely. Once they had fallen to within arm’s reach of the surface, resisting any further motion would require only the gentlest vertical thrust.

The ceiling of rock began tipping down toward Ivo’s side of the Mite, their descent propelling them around the Object ever faster. Carla found the sense of momentum more empowering than alarming; she’d had enough of waiting. She wanted to see a plain of orthogonal matter spread out beneath her, near enough to touch. This fragment of the primal world had traveled backward around the history of the cosmos; the world that had given birth to her ancestors had taken the opposite course. For a child of one to encounter the other would close that vast, magnificent loop—and the meeting that the Hurtlers offered with violence could here be made serene. With caution, serene.

Ivo took her hand. Did you see that?

What?

The flash, he replied.

Carla looked past him at the jagged brown rock, unchanging in the starlight. Perhaps the Object collided with specks of ordinary dust now and then. It was even possible that some fleck of material from the hull of the Gnat, or a particle of unburnt sunstone from their final burn, had just made its way to the surface.

She saw the next flash herself. It was less fierce than the ones they’d provoked from the Gnat, and much more diffuse—less a blazing pinprick than a brilliant daub of light. An ignition as dispersed as that wasn’t due to a fleck of anything.

What’s doing this? she asked Ivo. He didn’t have time to reply before the surface lit up again, a burst of blue-tinged flame spreading out across the rock, then quickly dissipating.

Us? he suggested.

Carla felt her muscles grow tense with fear, but his theory made no sense. How could they still be shedding anything, after the air had flowed over them for so long? Any loose material in their equipment or on their bodies should have been carried away into the void long ago by the relentless breeze.

What, exactly? she replied.

Ivo thought for a lapse or two, while another flash erupted on his left.

Contaminant in the air, he concluded.

Carla couldn’t see his face, which was turned toward the Object, but his posture was hunched in shame. Ivo had been responsible for filtering all the air they’d packed, ensuring that it contained no particulate matter. She couldn’t imagine him treating the task with anything but scrupulous attention.

But he wasn’t taking the blame for no reason; the symptoms lent his verdict a horrible plausibility. If the Mite’s would-be air shield was actually spraying traces of fine dust in all directions, that would explain why these ignitions were so much more dispersed than the ones brought on by the projectiles.

The flashes were coming every pause or two now, and the wall of rock was drawing closer. Carla struggled not to panic; the single worst thing they could do would be to aim an air jet straight at the surface in the hope of a swift ascent. All their tanks had to be treated as equally suspect: the contents of any of them touching the surface could engulf the Mite in a conflagration.

She made some quick calculations on her thigh. Jet four, six flickers, she suggested. Jet four was pointing back along their orbit; though the burst of air would be aimed horizontally, it would raise their velocity and reduce the curvature of their trajectory enough to cause them to ascend.

What about spillage? Ivo protested.

Can’t be helped. The jet’s nozzle would send out a wide spray, some of which was sure to reach the surface. But if they did nothing they’d remain on their original orbit, passing within a few dozen strides of the rock. The flames were probably reaching at least that high already, and with the source of contamination even closer the eruptions could only become more intense.

Shut off all air? Ivo replied.

Carla hesitated. Would that be wiser than risking the jet? The air shield was clearly more of a liability than a source of protection, but she couldn’t say the same about their cooling bags.

Hyperthermia? she countered.

Shield is worst thing, Ivo pointed out. Bags later, not for long.

He didn’t wait for a reply for the first step; he reached into the center of the Mite and closed the outlet valve on the air tank feeding the shield.

The blue flares persisted, undiminished, for so long that Carla came close to proclaiming that Ivo’s dismal hypothesis was wrong, and that they could use the air jet to retreat with impunity. Then, abruptly, the rock became dark.

Once it had actually happened, it was hard to think of this respite from the encroaching flames as a bad thing. But the fact that Ivo had been right about the cause didn’t mean his minimal air scenario really was the Mite’s best chance. If they did use the jet, how much spillage would there be? How high would the explosion reach? Would it spread out from the ignition site fast enough to catch them?

The truth was, Carla didn’t know. She couldn’t quantify any of these things.

How long, then, could they survive without air drawing heat from their bodies? People who’d lived through accidents in the void rarely had a chance to consult a clock, but Carla had heard claims that the limit was a couple of chimes.

The Object filled half the sky. Her irresolution had settled the matter: they were too close now to risk using the jet. All they could do was follow the orbit down.

Carla could see the plains of gray powderstone approaching, below her to the left but swinging toward her right, the wall of rock tilting and coming full circle. The scale was impossible to judge; she checked the clock. The lowest point on the orbit was still seven chimes away.

A wide, shallow crater slid by, its ancient walls broken like the ruined desert fortress her father had described to her as he recited a story from the sagas. As it passed, flames erupted along part of its rim and spilt across the ground. This was it: the meeting of worlds she’d longed for. With a pang of grief she thought of sweet Carlo, fighting so hard to keep her alive, poring over census records to plan their every meeting.

A trail of blue fire pursued the Mite, streaking across the pitted landscape. The light from it was dazzling, almost painful, but Carla couldn’t look away. Ivo reached up to the tank on his chest and shut off the air to his cooling bag. Moments later the flames subsided, but they did not die completely.

She squeezed Ivo’s hand, lost for words but trying to let him know that she didn’t blame him. He hadn’t forced her to join him. The ground was so close now that Carla could see the structure of the rock, the surface of coarse lumps and concavities about the size of her fist. It looked exactly like powderstone. Ivo’s bold plan to grab a sample here might even have worked, if not for the blunder that had rendered his air blades as suicidal as any hardstone chisel.

The flames were rising again, and gaining on the Mite. Carla checked the clock; the low point was still four chimes away. She turned down her cooling air as far as she could while still sensing some flow across her skin, but the effect on the height of the flames was slight, and soon overtaken by the Mite’s descent. She could feel the heat coming off the blazing ground now, worse than anything her own body could inflict on her.

She shut off the air completely.

The flames faltered, then winked out, leaving the Mite gliding over the starlit landscape. Carla felt a rush of euphoria, but time and geometry were not on her side. Once she and Ivo had both lost consciousness, their deaths would be guaranteed. Even if they were still alive at the point where it was safe to turn on the air again, they’d be oblivious to the chance to save themselves.

She stared at the useless air blades atop the workbench, angry now. Ivo had seen his grandchildren; maybe the folk saying was right after all. That sense of completion had made him careless with his own life, and now his sloppiness was going to kill her too. She thought of grabbing the stupid tools and aiming them at the ground, going out in a blaze of glory that would carve her own name into the sagas.

She saw the whole scene from outside her body: she was silhouetted against the inferno she’d made, one blade in each upper hand, the tubes that fed them running down into the Mite. It was a striking image, no doubt about that—but there’d be no witness to record her defiant pose.

The tubes.

She turned to Ivo; he was slumped in his harness, eyes closed. What was she waiting for—his permission to tear the device apart? Carla wrenched the tube off the right-hand blade, then reached down and pulled the other end free from the outlet of its air tank. With her lower hands she groped inside the bottom of the Mite, finding the clock whose dials she’d been checking. The mechanism was completely exposed; Marzio, bless him, hadn’t sealed it away behind decorative panels that would only have made repairs more difficult.

She could feel the shafts that led out to the dials: she was disoriented for a moment, but the one for counting flickers was easy to distinguish by its speed, and the one for pauses not much harder. Once she had those two fixed in her mind, the shaft she wanted—the shaft that turned once every chime—was easy to find.

She probed the space between the back of the clock face and the gear at the base of the shaft. The separation was more than the thickness of the air tube. Better more than less—but the fit would not be tight enough to keep the tube in place by friction alone.

She felt her way deeper into the flying workbench and found a rack of vials, a stock of reagents that Ivo had intended to use in his calorimetry experiments. Each vial was sealed with a thick blob of resin. Carla sharpened her fingertips and sliced the top half off one of the seals, then daubed the sticky resin over the shaft. She did the same with a second seal, using it to coat the center of the gear. Her body was starting to protest against the heat now; mites were crawling beneath her skin, and some pointless instinct was trying to tempt her with visions of a cooling bed of sand.

She bent the air tube, bringing the two halves together so the corner was crimped to an impassably narrow fold—probably not air tight, but the flow it allowed would be a tiny fraction of the flow through the unobstructed width. Then she passed the tube down to her lower hands and pressed the folded end against the resin-coated shaft.

Laboriously, she began wrapping the tube into a spiral, threading the long tails in and out of the narrow spaces of the clock. The tube fought against the curvature and broke free. She sliced off more resin from two more vials and spread it over the gear and the tube. Her skin was stinging all over now, and points of light were moving across her vision.

The tube stayed in place, curled five times around the slowly turning shaft. Carla pulled apart the join between her cooling bag and its supply tank, and interposed the crude timer.

She opened the valve on the air tank slowly, afraid that too much pressure would tear the tube free. She stopped at the point she remembered by touch—well short of fully open, but where she’d last felt enough air flowing across her skin to make some difference. Nothing was coming through the pinch, and there’d been no tell-tale bounce of the tube unraveling.

She was dizzy now, too disoriented to trust herself to check anything she’d done, let alone try to change it. The lights behind her eyelids swarmed and chittered. She tried to picture Carlo, his body pressed against her, but then part of her refused to be fooled or comforted and the image of him spun away into the whiteness.