Greg Egan - The Arrows of Time

‘I like it,’ Agata replied. ‘It’s meditative.’

‘That’ll wear off,’ Celia promised.

Agata turned into a dusty corridor and followed it for a few stretches. The entrance to her section of the cooling system was easy to find: moss had eaten a great concave chunk out of the wall beside it, and the usual red glow was criss-crossed with threads of yellow. She slid the key into the access panel and strained to pull it open.

A short ladder led down into the tunnel. The breeze pulsing through the darkness chilled Agata’s skin, but after the first shock it wasn’t unpleasant. The ceiling of the tunnel was too low for her at her normal height, but she only had to resorb half a span from the top of her legs and she fitted comfortably. She started walking, one hand on the wall to guide her. The splotch of red light spilling in from outside shrank in her rear vision, and when it was gone she was in utter blackness.

A saunter or two down-axis, in a set of reaction chambers carved into the lode of sunstone that had once been destined to be burnt as rocket fuel, a decomposing agent was turning that fuel directly into gas – without the usual accompaniment of light and heat. The gas built up a considerable pressure, then as it forced its way out against the resistance of a spring-loaded piston, it grew colder. This was much more efficient than the old system that had used the exhaust from burning fuel as its starting point, but the moss that coated the mountain’s walls grew so vigorously beneath the new kind of breeze that it threatened to clog all the cooling tunnels.

As Agata’s eyes adjusted to the darkness, she began to see the small red patches of new growth around her. A shift ago, she’d left this whole section as bare rock, but it didn’t take long for fresh spores to blow in and find purchase. She took the coherer from her tool belt and aimed it at the nearest colony, closing her eyes against the flash so they wouldn’t lose their sensitivity.

Three stints into the strike, she still found the job absurdly satisfying. The work was vital, and she could see the results of her efforts immediately. That the moss returned so quickly didn’t bother her at all, so long as she could keep it under control. Better to walk the length of the tunnels regularly, searching for these early infestations, than wait for the walls to become so encrusted that they’d need to be scraped clean with a hardstone blade.

As she advanced along the tunnel, scanning the blackness ahead for another faint speck of moss-light, Agata realised that this was exactly the kind of task during which she once would have ended up pondering the questions Lila had berated her for neglecting. She had only ever made progress on her research when the problem she was tackling rose up unbidden to occupy her mind in idle moments – whether she was walking or eating, cleaning her apartment or lying in bed waiting for sleep, her thoughts would be dragged back to the same place, to chip away at the obstructions until they yielded. At her desk, at her console, she could analyse her own earlier work in detail, or carry out a lengthy new calculation, but entirely new ideas only came to her when she was meant to be doing something else.

Now, though, when her thoughts weren’t gravitating to the subject of Lila’s criticism or scrutinising their own dynamics, the only thing that occupied them effortlessly was speculation on the kind of news that the messaging system would bring. It wasn’t intrusive or disturbing – any more than her obsessive return to the niggling questions of curvature and entropy had been – but the entire space in which her creative work had once taken place had been thoroughly colonised by the interloper.

But the cure wasn’t far away: once the system was completed she could hardly remain in the thrall of revelations still to come. And was it so terrible if she found herself distracted for a while by the prospect of learning the future of the Peerless ? She had less than two dozen stints to wait – and, thanks to the strike, she could still do useful work in the meantime. Even if Lila was right and some part of her was refusing to accept that she could expect no help with her research, once she’d seen the actual contents of her messages any hope of impossible cheat notes would soon dissipate. In most respects her life would return to normal, but her spirits would be bolstered by the news of the mountain’s safe return. She would resume her work with new energy and optimism, not because her future self had furnished her with theorems she was yet to prove, but because she’d know that her whole life, and the lives of everyone around her, were part of a great struggle whose end was in sight.

Agata felt the tremor in the rock beneath her and braced herself instinctively, her tympanum growing rigid, rendering her protectively deaf. She lost her footing and fell to the floor, disoriented, unsure if the shaking had been enough to unbalance her or whether she’d been struck down by a shock wave in the air.

She curled up against the cool stone, waiting for worse, waiting for the mountain to split open and spill her out into the void. But the rock was still, and when she forced the membrane around her throat to relax she heard nothing but distant creaking.

As she clambered to her feet the air on her skin smelt acrid. She fumbled for the coherer and flashed it briefly, averting her eyes from the dazzling spot it made on the wall; the secondary reflections lit up the rock around her and showed a fine haze hanging in the air. The breeze from the cooling chambers was as pristine as ever, so the smoke must have entered the system somewhere ahead of her, up-axis, with enough pressure to force it back against the usual flow.

Agata turned and began retracing her steps in the blackness. She had no experience with which to gauge the intensity of the blast. There’d been plenty of accidents in the workshops of which she’d been unaware at the time, but as the cooling tunnels linked every part of the mountain she had to expect to feel the effects far more strongly here. With no basis for comparison, she shouldn’t rush to any wild conclusions about collisions with infinite-velocity rocks.

It was only when she reached the entrance to the tunnel and began climbing the ladder up into the moss-light that she realised how badly she was shaking. She steadied herself as she approached the office, afraid of Celia’s disdain if it turned out to be a routine part of her job that every tiny bang the chemists set off would echo down the tunnels and knock her off her feet this way. The cooling air fed their ventilation hoods, where they carried out some of their most dangerous experiments. Maybe she should have been expecting this concussive initiation all along.

When Celia noticed Agata approaching, she didn’t seem to be in the mood to mock her. As Agata drew closer she saw that a news inset had opened on the console’s display screen, but the angle made it impossible to read.

‘What happened?’ she asked Celia. ‘I felt it in the tunnel, but I didn’t know exactly…’

‘There’s been an explosion in one of the workshops.’

‘The chemists’?’

Celia said, ‘The instrument builders’. The one where they were working on the cameras for the messaging system.’

‘We can keep you locked up for as long as we like,’ Maddalena told Ramiro. ‘You could spend the rest of your life in that cell – with no visitors, no work, no diversions. Nothing at all to occupy your mind.’

‘Is that right?’ Ramiro replied. ‘Yalda would be proud of you.’ He glanced around the interrogation room, wondering if Greta would ever join them again. She’d sat in on the first few sessions and, as coldly as she’d treated him, the presence of even one familiar face had been enough to make him feel less isolated. But then, perhaps that was why she’d stopped coming.