The Arrows of Time: Orthogonal Book Three (37 page)

He turned to Agata for support, but her confidence was wavering. ‘I spent years in that state myself,’ she admitted. ‘It’s not that difficult to achieve.’

Azelio lowered his gaze. ‘We should start our own evacuation, then. Bring as many people as we can on board.’

‘I’d have no objection to that,’ Tarquinia said. ‘But once we dock, whatever happens to the
Surveyor
will be out of my hands.’ Ramiro had a brief fantasy
of the
Surveyor
orbiting the mountain at a safe remove while evacuees jetted across the void to join them – but unless they were lugging six years’ worth of food there
wouldn’t be much point. And even then it could only end badly, once the lucky few had to start turning the rest away.

Azelio’s expression changed abruptly. He buzzed with a kind of pained relief, as if he’d just decided that his fears were not only groundless but embarrassingly naïve.
‘Whatever else we’re missing,’ he said, ‘we know the
Peerless
’s location when the disruption takes place. If we were going to be hit by something, we could
avoid that just by changing course: we wouldn’t happily steer straight for the meteor.’

Ramiro said, ‘Maybe they will change course. Maybe they already did. Either way, the disruption still happens.’

‘Exactly!’ Azelio replied. ‘So it can’t be down to a collision. If changing the location were enough to stop it happening . . . it couldn’t happen. On Esilio, we
were never forced to do anything against our will, so how could a mountain full of people with no intention of dying be forced to choose a fatal trajectory? Stumbling blindly into a collision would
be one thing – but how could it happen with foreknowledge?’

Agata considered this. ‘I think your argument would hold if we knew the cause with certainty. But it’s not so clear-cut when we’re less informed – when we’re not
sure that the disruption will be fatal, and we’re not sure that it involves a collision at all.’

Azelio scowled. ‘So because we can’t
know
that it’s a collision . . . it’s more likely that it is?’

‘Is that really so strange?’ Agata replied. ‘If everyone on the
Peerless
was confronted with the certain knowledge that the course they were on was suicidal, then
there’s no way they’d persist with it – unless some freakishly unlikely set of events undermined the efficacy of their intentions. With three years’ warning to achieve the
necessary swerve, what could possibly stop them? The engines would need to drop off, and every last person capable of improvising any kind of substitute would need to die of some convenient
affliction. I don’t believe for a moment that the cosmos contains anything so unlikely.

‘But taking an unknown risk is different. If we don’t know exactly what would make us safe, there’s no need for an endless barrage of misfortune to keep us from finding the
right solution.’

Azelio abandoned the argument and the cabin fell into a despondent silence. Ramiro almost wished he hadn’t argued against Agata’s first, cheerful verdict. He couldn’t imagine
what Azelio was going through, but even his own brief, hallucinatory experiences of fatherhood offered a hint. Nothing could be more harrowing than being forced to contemplate the death of the
children you’d promised to protect.

‘Maybe the Councillors are going to shut down the system themselves,’ he suggested. ‘Just because Greta denied it doesn’t mean they won’t do it.’

‘But why would they?’ Tarquinia asked irritably.

‘If it’s a choice between that and the destruction of the
Peerless
,’ Ramiro replied, ‘then I don’t believe they’d choose the latter. Whatever their
flaws, they’re not that deranged.’

Azelio was taking no comfort from the theory. ‘But are they deranged enough to think that that’s their choice? If you can’t avoid a meteor by choosing your trajectory, how can
you avoid it just by switching off the messaging system?’

Agata had a different objection. ‘If they did shut down the system, wouldn’t that be an unsupported loop? They’d only be doing it because they learnt that it was going to
happen.’

‘There’s not much complexity to it, though,’ Ramiro argued. ‘It’s hardly the same as learning a whole new theory of the vacuum from your future self; all they have
to do is flick a switch.’

‘The Council wouldn’t want the mountain destroyed,’ Tarquinia agreed, ‘but they might well share Azelio’s view about their choices. They’ve come into this
looking for a vindication of the system – so I don’t see anything inconsistent if they find themselves receiving three years’ worth of reports from the future that all describe
them clinging to their original position: that the whole thing’s a boon, and there couldn’t possibly be any reason to shut it down deliberately.’

Ramiro ran his hands over his face. ‘Forget the Council, then. Let’s assume that there’s no chance of them causing the disruption. What’s the next most benign
explanation?’

‘We could do it ourselves,’ Tarquinia suggested.

‘How?’ Azelio demanded. ‘What could we do that would be harder to see coming than a meteor at infinite speed?’

‘I have no idea yet,’ Tarquinia admitted. ‘But at least we’re isolated from the messaging system for a few more stints. We ought to be less vulnerable to the innovation
block.’

Agata said, ‘But in the end, it would only be the shutdown itself that would have driven us to find a way to cause the shutdown.’

‘And that’s meant to stop us?’ Tarquinia was undeterred. ‘If that kind of loop really is too unlikely to be true, then we’ll find out eventually. But the only way
to know is to try it.’

Ramiro recalled his own farcical attempt to steal the authorship of the fake inscription from her. It still seemed wisest to keep that to himself, but he didn’t need to confess anything to
make the case for a more robust strategy.

He said, ‘There are plenty of people on the
Peerless
who could have planned this shutdown long before they heard about it.’

‘You mean saboteurs?’ Agata asked coldly. ‘The people who murdered the camera team? You want to replace a meteor strike with a bomb?’

‘Of course not.’ Ramiro spoke more carefully. ‘Most of the anti-messagers found those murders abhorrent, but a group of them could still be planning a way to cause the
disruption without hurting anyone. And if they’re intent on using explosives at all, we can try to replace that with something better.’

Tarquinia understood. ‘We have seven stints to work out a plan of our own, and then we can try to sell it to these would-be saboteurs. That way it becomes a hybrid effort: their motives
predate the news of the disruption, but if they’ve left the details too late we might be able to offer them a technological edge.’

Azelio hummed with frustration. ‘What’s all this talk of replacement? If a meteor is going to hit us, it’s going to hit us! You can devise as many ingenious plans as you like
to try to sabotage the system at the very same moment, but if there’s a rock on its way, nothing you do is going to make it disappear.’

‘
If
there’s a rock on its way, that’s true,’ Ramiro conceded. ‘But until we know that there is, why should we assume that? The history of the next twelve
stints ends with the messaging system failing; we’re about as certain of that as we can be. Some sequence of events has to fill the gap between that certainty and all the other things we
know. So which snippets would you rather the cosmos had on hand to complete the story? Just one, where a meteor hits the
Peerless
? Just two: a meteor, or a bomb? Making our own preferred
version possible won’t rule out everything else – but if we don’t even try, we’ll rule out our own best hope entirely.’

Agata brought a schematic onto her chest. ‘Whatever the details of the final design they used, each channel must have components something like this.’

Ramiro hadn’t thought about the technical aspects of the system for years, and as he reacquainted himself he was surprised by its apparent fragility. ‘Disrupt the
light for a flicker, and the flow of information is cut. There’s no need to damage anything.’ Although the messages were constantly being converted into a less transient form to be
boosted and re-sent, that version of the data only endured forwards in time – it couldn’t bridge a gap into the past. He’d often pictured the messages as a storehouse of
documents, a kind of future-archeological find, but they were much more vulnerable than anything written on paper, or even in the energy states of a memory chip.

‘Could we launch some small objects into the external light paths?’ Tarquinia wondered. ‘If each one starts on the mountain close to one of the channel’s outlets, it
could probably occult the target star without being picked up by a surveillance camera first.’

Azelio said, ‘The outlets will have to be on the base of the mountain, won’t they?’

‘Yes,’ Tarquinia replied. ‘Unless they’ve turned everything around while we were gone.’

‘We’d need to know exactly which orthogonal stars they’re using,’ Agata pointed out.

‘Maybe our collaborators will have that information already,’ Ramiro suggested. ‘So if we can offer them some miniature automated craft to fly up from the mountain and block
those stars, why wouldn’t they use them?’

Azelio said, ‘So who’s going to build these things without being noticed? They’ll need accelerometers and photonics in order to navigate with any precision. If we make them
ourselves on the
Surveyor
, we won’t stand a chance of smuggling them out when we dock. But on the
Peerless
, all the workshops and stores will be under
surveillance.’

‘We could release them before we dock,’ Agata suggested. ‘Send them out to hide somewhere. If they’re small enough, and we time the whole thing carefully, they could pass
from the
Surveyor
to the slopes undetected.’

‘And then what?’ Azelio pressed her. ‘They adhere to the slopes somehow, and then crawl towards the base – like insects crawling along a ceiling?’

‘Yes.’ Agata wasn’t backing down, but the proposal was growing more ambitious by the moment.

‘And then later,’ Azelio said, ‘since we won’t know the coordinates in advance, we have to be able to instruct them, remotely, to crawl to a particular take-off point and
then fly along a certain trajectory. Without the signal being detected.’

Tarquinia disagreed with his last claim. ‘If a brief encrypted signal is picked up by the authorities, what can they do about it? So long as they can’t pin down the exact source or
destination, mere detection need not be a problem. Even if they take it as a sign that some form of attempted sabotage is under way . . . they would have had that possibility in mind for the last
three years, regardless.’

Azelio hesitated. ‘So why would they even try to stop us? They
know
the disruption is going to happen – so unless all this clandestine activity is irrelevant and a meteor is
going to be responsible, this is a battle they know they can’t win.’

‘They’re not going to give up, any more than we are,’ Agata replied. ‘Do you see any sign in what we’ve heard from the mountain that the Council have resigned
themselves to a state of fatalistic powerlessness?’

‘No,’ Azelio conceded.

‘Think of it as a kind of equilibrium,’ Tarquinia suggested. ‘I’m sure there are limits to how far the Council would go to try to stop the inevitable, but there must be
limits, too, on how supine they’ll become: they’re not going to shut down the system themselves, or release all the anti-messagers and let them go on a rampage with mallets.
They’ve taken a stance and they’re going to pursue it as far as they can. When this is over they’ll be looking for a political advantage in the details of the fight, as much as in
the outcome.’

Azelio was looking disoriented. ‘I want this to work,’ he said haltingly. ‘But every time I stop and think about it, it feels as if all we’re doing is playing some kind
of game. Shouldn’t we be trying to build better meteor detectors? If we really are the only people left with any hope of innovating, why not design a device that could actually save the
mountain – instead of one for faking its death?’

Agata said, ‘If we saved the mountain from a meteor, don’t you think we’d know about it?’

‘I have no idea.’ Azelio rose from his seat. ‘But what we’re doing now is pointless.’ He walked out of the cabin.

In the silence, Ramiro felt his own confidence faltering. ‘I don’t know how to reason about this any more,’ he said. ‘If it’s a meteor that could actually kill us,
isn’t that where our efforts should go? Forget what the messages say or don’t say about it: if we do our best to build something useful, how can that fail to make a
difference?’

Agata inclined her head, expressing some sympathy with the impulse. But she wasn’t swayed. ‘I was the one who tried to argue that there’s no such thing as an undetectable
meteor – but what do we have on board for tackling that problem? A single time-reversed camera, and no facilities for building new photonic chips or any kind of high-precision optics. Even if
we came up with a glorious new design, how are we supposed to manufacture a whole network of surveillance cameras and get them deployed? They can’t just be drifting around the mountain
detecting hazards for their own amusement – if they find something, they have to be able to trigger either a coherer powerful enough to deflect the thing, or start up the engines and make the
whole mountain swerve. Do you really think we’d be able to do that in secret?’