The Arrows of Time

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.’

28

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.