Greg Egan - The Arrows of Time

Verano glanced at Greta. Greta said, ‘Once you’ve made an application and agreed to the confidentiality conditions, we can discuss whatever details you like.’

Tarquinia was taken aback for a moment, but she accepted the reply without complaint.

Verano took Tarquinia closer to the hull and the two of them began chatting with some of the masons. Greta turned to Ramiro. ‘Still thinking of doing a Eusebio?’ she asked. ‘Letting your comrade fly alone?’

‘I wasn’t serious,’ he protested.

‘Of course not.’ Greta reached down and picked up the end of his chain.

Ramiro groped for an insult, but his mental scrabbling yielded an entirely different weapon. ‘You’ve got a working version of the camera,’ he realised. ‘What is it – some prototype that survived the bombing?’ How else would they navigate to the edge of the orthogonal cluster, if not by imaging the time-reversed stars?

Greta said, ‘You don’t get to ask questions like that.’

Ramiro was sure now that he’d guessed correctly. Tarquinia had probably worked it out too. It wasn’t something he’d want the whole mountain to know – lest the same deranged killers behind the bombing decided to target the Surveyor itself – but it was always pleasing to be a little less in the dark than his jailers wished.

‘You’d better think up a good cover story,’ he suggested. ‘A new generation of accelerometers, maybe? I’ve been a bit distracted, but other people won’t be so slow.’

Tarquinia was buzzing with mirth; Verano had just explained the way the Surveyor ’s toilets would work. Ramiro was unspeakably happy at the thought of having her along on the journey – and if he was trapped now, so be it. He’d wanted to stay strong enough not to back out, and if Tarquinia’s presence would shame him into honouring his commitment that was nothing to lament.

Greta said, ‘All I’ve ever done is work to keep the Peerless safe. I think you can trust me to do the same for the Surveyor .’

‘Perhaps.’ Ramiro couldn’t stop himself goading her when he had the chance, but she’d already proved her resolve to make the mission successful. ‘And I think you can trust me not to flee custody and disappear into some anti-messager safe house.’

‘Perhaps.’ Greta took a key from a pocket in her thigh, then reached over and unlocked the fetter. Ramiro slid the chain free, then eased the bar out of his flesh and let the whole thing clatter to the floor.

He watched Tarquinia haltingly ascend the ladder so she could look down into the Surveyor for herself. Six years to Esilio, six years to come back, then six more if he joined the migration. He’d be at least three dozen and four years old by the time he was walking free across the plains of his new home – and he’d need to outlive the average male in his line by five years to get that far.

He’d managed to constrain his entire future as rigidly as any message encoded in time-reversed light could have done. But if he looked at the alternatives honestly, they were all worse.

‘And now you’re dead.’

Agata could no longer see Tarquinia in the whirl of stars and shadow around her, but this flat pronouncement came through the helmet’s link as if the woman were right beside her.

‘I’m sorry.’

‘How did it happen?’ Tarquinia demanded. For a bell and a half she’d been oppressively close, observing every tiny mistake Agata made and dispensing acerbic reprimands, but even the distance this mishap had put between them wasn’t going to silence her.

‘I don’t know! The tank just slipped out of my hands.’

‘Just slipped? Why do you think you’re spinning like that?’

‘I must have opened the valve too soon,’ Agata confessed.

‘Well… don’t ,’ Tarquinia replied irritably.

‘I’m sorry,’ Agata repeated.

The point of the exercise had been to try to use her cooling bag’s air tank as an improvised jet. She’d understood perfectly what the prerequisites for a successful burst would be: a tight grip on the tank and a thrust aimed straight at her centre of mass. But she’d held the tank wrongly, or slipped, or panicked.

She wasn’t actually going to die of hyperthermia; she had two small emergency canisters strapped to her belt. She managed to detach one and connect it to the bag’s inlet without mishap. The cool rush of air felt unearned, but then, if the Surveyor broke apart halfway through the mission, casting them all out into the void, she doubted that a few dextrous manoeuvres with her air tank would be enough to save her.

Agata saw a figure approaching out of the mountain’s shadow, a little closer each time it spun into view. It was easy for Tarquinia: she had one of the new jetpacks strapped to her body. The six nozzles were all controlled by photonics, their thrust automatically balanced so they imposed no torque at all. Bulky as the things were, Agata decided that she was going to wear her own pack for the entire twelve years of the mission, rendering these dispiriting training exercises redundant.

Tarquinia collided with her roughly, grabbing hold of Agata’s arm. Agata’s gut twitched; she was tumbling in a completely different plane now, and the sudden shift in the flow of stars across her vision was more wrenching than the impact. Tarquinia seized Agata’s other shoulder and embraced her, pulling the two of them into equal intimacy with the slab of equipment that covered Tarquinia’s chest. Then she must have told the jetpack to kill their rotation: the torque itself was imperceptible, but it looked as if someone had slammed a giant brake against the spinning black bowl that held the stars.

When the sky had ceased turning, Tarquinia released her grip and hooked Agata’s belt to the front part of the jetpack.

‘Are you all right?’ she asked, less brusque than usual.

‘Yes.’ Agata realised that she’d been shivering.

‘I know it isn’t easy, but you have to reach the point where things like this are just instinctive.’

‘I understand.’ Agata gazed past her into the dark hemisphere that had once held the orthogonal stars. They were still out there, in the blackness, but her own eyes were now emitting the light she no longer received from them. ‘I don’t think I can do this,’ she said. ‘I think I made a mistake.’

Tarquinia interposed her helmet into the view. ‘You want those light-deflection measurements, don’t you? I thought the fate of the cosmos hung on those fractions of an arc-flicker.’

‘You’re the astronomer. You could do a better job at that than I could.’

Tarquinia said, ‘I’m not taking any measurements that aren’t essential for navigational purposes.’

Agata doubted she was serious about that. ‘If my real job is to stop Ramiro going crazy and ramming the Peerless , why don’t they choose a pro-messager pilot to keep him in check?’

‘I don’t think they’ve been overwhelmed with applications,’ Tarquinia replied. ‘Anyway, that’s just politics; for practical deterrence, you can bet there’ll be some tamper-proof way to incinerate the Surveyor with the flick of a switch from the Council chambers.’ She squinted at Agata through their faceplates. ‘I’m not going to force you to do anything. If you want to go back to the airlock right now, that’s fine with me.’

Agata was tempted, but she stopped herself. If she pulled out of the training now there’d be no chance to reconsider. ‘Why did you volunteer?’ she asked Tarquinia. ‘Do you think there’d be a war, without the Surveyor ?’

Tarquinia didn’t reply immediately. ‘I’m still hoping that we’re not that suicidal, but if we are I wouldn’t pin my hopes on Esilio.’