The Arrows of Time: Orthogonal Book Three (42 page)

‘No.’ Tarquinia shifted uneasily.

‘So . . . ?’

‘We’ll go ahead,’ she said. ‘Nothing else makes sense. Maybe I’m just not accustomed to things slotting into place so perfectly. It used to be that anyone who knew
from the start what to say to win you over was setting an ambush. These days, maybe all it proves is that they bother to read their messages.’

Giacomo handed over the data link, a shiny black slab of photonics about five scants across.

Ramiro inspected it. ‘That’s perfect,’ he said. He’d had no hope of getting hold of anything like this himself. ‘How do you get past the inventory
checks?’

‘You can swap an inert mock-up for the real thing,’ Giacomo explained. ‘If you do it the right way no one will notice for years.’

Ramiro formed a pocket and hid the link. ‘Do you have the coordinates for me?’

‘Yes, but we should get the other business out of the way first.’ Giacomo paused expectantly.

‘Of course.’ Ramiro had sat down with Tarquinia for a bell the night before, refining the sketches from memory. They’d kept no records of the occulters’ design on paper
or in photonics, and not merely to avoid discovery; they hadn’t actually anticipated any need for it.

He summoned the final drawing onto the skin of his chest, with all the details and dimensions that Giacomo had requested. The explosives caches would need to have been carefully designed if they
were to grab the occulters and ride them – without jamming the mechanism or fatally unbalancing their hosts. Still, Ramiro’s first impulse when asked for the plans had been to challenge
his accomplice, jokingly, to display them first. But the information would still need to pass between them in the conventional direction at some point, and Ramiro hadn’t really wished to be
confronted with an unarguable proof that he would agree to the transaction eventually.

Giacomo dragged himself closer along the guide rope. ‘Do you mind if we do this by touch? My visual memory isn’t so strong, and cameras are a security risk.’

‘All right.’ Ramiro hadn’t been expecting this, but he had no reason to object. He moved forward and let Giacomo embrace him, and as their skin made contact the gentle pressure
rendered the ridges of the drawing palpable to both of them.

‘When will you send it?’ Ramiro asked.

‘Tonight.’ Giacomo separated from him. ‘In three pieces, hidden in pictures of my children.’

‘Why not just encrypt it?’ Ramiro hoped nothing had shown on his face as he heard the phrase
my children
. He would never have picked the man for a Starver, but then, once
their children were born they had no reason to starve.

Giacomo said, ‘The authorities can tell from the size of the message that it’s unlikely to be text, and encrypting an image attracts more suspicion.’

‘Right.’

‘I’ll give you the coordinates now.’

Ramiro waited for him to hand over the paper, but then he understood that this exchange was to be conducted the same way.

As they embraced again, Ramiro concentrated on the numbers, committing the pattern of ridges to memory. As a child, he’d passed messages to male friends this way, making a joke out of the
harmless intimacy’s mimicry of the forbidden act. But the skin that was pressed against his own now hadn’t mimicked it, it had triggered the real thing.

‘Do you have them all clearly?’ Giacomo asked.

‘I think so.’ Ramiro pulled away, averting his gaze, unsure what he was feeling.
Envy?
If Tarquinia had ever really died in his arms, it would have been unbearable. Why
should he envy a man who’d lost his co?

Giacomo said, ‘The angle of approach and the orientation are crucial. We’ve made sure that the hooks are compatible with the dimensions of the arms, but if your machine comes in too
steeply or the arms are turned the wrong way, it won’t engage the hooks at all.’

‘I understand.’

‘And the retreat’s just as important,’ Giacomo stressed. ‘If you pull away vertically, the resin won’t give. The rope will snap, or something else will
break.’

‘We’ll follow the whole flight plan as closely as we can.’ Ramiro reviewed the list, bringing the figures back onto his skin as he checked them. ‘What are those last sets
of numbers?’

‘The coordinates of the light collectors.’

Ramiro hadn’t expected to be given the targets themselves until he’d reported back on the first stage of the process. ‘So that’s it? We just fly the occulters there . . .
and then what?’

‘The bombs are all controlled by timers,’ Giacomo explained. ‘All you need to do is get them to the right place.’

‘What do we do if something goes wrong? How can we contact you?’ Ramiro was prepared to accept responsibility for the occulters, but if anything else malfunctioned he’d have no
idea what the options might be.

‘Nothing goes wrong,’ Giacomo assured him.

‘You can’t know that,’ Ramiro protested. ‘Not after the private messages are squeezed out—’

‘That late?’ Giacomo paused, struggling to frame an answer, as if he’d lost the habit of imagining anything beyond the reach of his foresight. ‘The disruption is
ours,’ he said finally. ‘We’ve been planning it for longer than the system’s been in existence. We know that it happens – and we know that we’re trying harder to
make it happen than anyone else. So how can we possibly fail?’

Ramiro moved away from the console and let Tarquinia check the alignment of the link against her own calculations. They’d set the beam to be as narrow as they dared, to
minimise the chance of anyone detecting it on its way out to the slopes. But if they failed to aim it at the precise location where they’d left the first occulter clinging to the rock
they’d be risking discovery for nothing.

‘This looks right to me,’ Tarquinia said.

‘Are you sure?’

‘In the end it’s just arithmetic and geometry,’ she replied. ‘If I do it a dozen more times I’ll still get the same answer.’

Ramiro had already entered the coordinates of the nearest cache into the software. He tapped a key on the console and a tight burst of UV erupted from the link. The confirmation came back
immediately: the occulter had received the message and was proceeding to act on it.

‘Perfect!’ Tarquinia declared.

‘So far.’ It would take the occulter three days to crawl across the mountain to its first rendezvous. Ramiro pictured the prototype clanking down the plank towards him, back on the
Surveyor
. They’d made allowances for the machines losing their footing and needing to recover, but the complex manoeuvres required to pick up the cargo would cut into the air supply,
and the extra mass being lugged around would shrink the margin for error even further.

Tarquinia said, ‘Next target.’

Their run of luck continued for a while, but the fifth occulter failed to reply. Ramiro rechecked the direction of the link, then broadened the transmission, but it made no difference.

When they’d released the occulters from the
Surveyor
each one had been given preassigned coordinates, but if the composition of the rock proved unsuitable they were to try again
at a number of adjacent sites. A pseudo-random algorithm varied the coordinates; knowing the seed for it they could match the sequence exactly.

After a dozen steps, Ramiro gave up. If the occulter hadn’t found a secure purchase by then, it would not have had enough air left to be of any use to them even if they could locate
it.

‘One in five,’ Tarquinia said. ‘We can live with that.’

By the end of the day they’d set a dozen and three occulters in motion and given up on three.

‘If Giacomo had stayed in touch with us,’ Tarquinia mused, ‘he could have spared his people the trouble of planting three of those caches.’

Ramiro said, ‘Maybe. Or maybe we’ll fumble the pick-ups on three of the others and have to go back and use the ones that seemed superfluous.’

‘That’s true.’ Tarquinia reached across and squeezed his shoulder. ‘We’re doing well.’

Ramiro was exhausted. He stared across the room and tried not to think of the machines scuttling along the slopes; the more he visualised them, the harder it became to avoid picturing a cog
jamming or a drill bit coming loose. ‘At the turnaround, all our biggest problems had been solved,’ he said. ‘Every traveller before us had put up with far more hardship and
uncertainty than we were facing then. So how did it come to this? Why are we the idiots who could lose it all?’

‘Stop thinking about it.’ Tarquinia took him by the arm and led him through into the bedroom.

When they’d finished, Ramiro clung to her body angrily. He’d wasted half his life on this imitation of fatherhood. If he hadn’t wanted the real thing, why did he keep chasing
this shadow? He was as much a slave now as if he’d meekly followed his uncle’s commands.

Tarquinia eased herself out of his embrace.

‘What happens afterwards?’ he asked her. ‘After the disruption.’

‘After the disruption,’ she said, ‘life goes back to normal.’

Agata ascended the stairs slowly, her gaze cast down at the moss-lit rock, hoping that if anyone was watching her she’d appear suitably distracted: a moody theorist
wandering the mountain, oblivious to her surroundings. Though every ordinary resident of the
Peerless
surely knew the size of the excluded zone around the axis, she hadn’t been able
to bring herself to ask Serena or Gineto to tell her. There was no way to phrase the question innocently: whoever she consulted, however obliquely, would be instantly burdened with the knowledge
that she was contemplating sabotage. Which might have led nowhere, or might have taken her rapidly to a place she didn’t want to be: finding a way to reassure an alarmed friend that she
hadn’t gone over to the side of Medoro’s killers, but was actually striving to undermine them.

To make any progress on that task, she needed a rough idea of the dimensions of the messaging system. It was safe to assume that the designers had made every channel as long as possible, running
close to the full height of the mountain, so once she knew how close to the axis the public were permitted to travel she’d have some sense of the mirrors’ width and the volume of each
enclosed light path.

As Agata’s weight diminished, she continued upwards, using the guide rope beside her. The ancestors couldn’t tell her how to halt the system, but they must have chosen her for a
reason – and the only hint they could give her had to be encoded in that choice itself. She had measured the bending of light by Esilio’s sun, hadn’t she? There was no prospect of
using gravity to distort the light paths in the messaging system, but gravity wasn’t the only way to modify light’s passage.

A woman passed her, descending, murmuring a casual greeting. Agata had chosen the stairwell at random; she had no reason to believe that she was heading for an entrance to the facility itself.
The usual tiers of apartments here should simply come to an end a little sooner than they had before the system was built.

Above her, less than a saunter away, the twelve long tubes would run from mirror to distant mirror, carrying messages from the future in beams of densely modulated time-reversed starlight. The
tubes would be sealed against contamination – against dust or smoke that might scatter the light – and perhaps the Council had made an effort to render them vacuum-safe, in case the
ends were breached and they were opened to the void. But that would be a matter of structural reinforcement to limit the damage from a sudden pressure difference, not a matter of impermeability.
There was no such thing as a hermetic seal on a container of that size. At the very least, particles of air would be constantly diffusing in and out of the tubes.

For most purposes, air was air. So long as it was chemically inert and dense enough to serve the crucial role of carrying heat away from bodies and machinery, any finer details were of secondary
importance. When the cooling system had switched from using the old engines’ exhaust to the gas produced by cold decomposition of sunstone, no one would have much cared that the range of
particle sizes was different. But there were countless variations on the basic theme of a stable ball of luxagens, and different mixtures had different properties. The speed of each frequency of
light was slightly different in air than in a vacuum, and the precise value depended on the precise composition of the air.

Agata reached the top of the stairs. A sign right in front of her spelt it out: LAST EXIT. She left the stairwell and dragged herself along the corridor, past the doors of the apartments. The
Council would have left a large enough buffer above this unrestricted area so that a bomb planted here could not have breached the nearest of the tubes. But she had a number now, good enough to
feed into an order-of-magnitude estimate: how fast could she expect a change in the air to diffuse through a resin seal into the tubes that contained the light paths?

Air was air, no one would feel a thing. But if she could make it happen, there’d be no need to damage a single component of the messaging system. The exquisitely calibrated timing of the
data fed into each tube would include allowances for ordinary variations in the ‘delay’ created by the light bouncing from mirror to mirror, but once it drifted beyond that range and
the signal was scrambled beyond recovery, there’d be nothing that the system could do about it – least of all send a message into the past to warn the operators of the nature of the
problem.

Back in her apartment, Agata sat at her desk and worked through the calculations. If she could add a component to the air that was significantly lighter than the smallest
particles in the present mixture, it would naturally rise towards the axis and diffuse into the imperfectly sealed tubes. Though a particle of air in isolation had almost no external field, each
light wave that passed over it distorted its shape sufficiently to spoil the usual cancellation between the luxagens, and the secondary wave generated by that process combined with the first to
slow it down.