‘Maybe a few ended up on porous rock,’ Tarquinia conceded. ‘And of those that fell loose, maybe one or two failed to reattach. But that’s why we made spares.’

‘Would we be part of Giacomo’s plan at all, if we weren’t going to have at least twelve survivors to offer him?’ It wasn’t a rhetorical question; Ramiro was never confident about the possibilities until he’d talked them over with someone else.

‘He wouldn’t hear the bad news unless he stayed in touch,’ Tarquinia reasoned. ‘So even if the occulters have all disappeared into the void, he couldn’t simply shun us before we’d worked that out together. But I can’t see why he’d claim that all his hopes were resting on us if it wasn’t true. I think the plan must keep holding together – at least for as long as ordinary people can keep sending back news.’

They had both heard from friends that, three days before the disruption, official communications would start taking up so much bandwidth that no private messages would be able to get through. If the occulters did fail, the failure lay somewhere beyond that horizon.

Ramiro was heading home from the food hall when a man bumped into him in the corridor, breaking his hold on the guide rope. As etiquette demanded they both reached out to steady each other, trying to kill the motion that the collision had imparted before they sent each other crashing into opposite walls. The manoeuvre succeeded, and they both muttered embarrassed apologies, but as they separated the man passed a slip of paper into Ramiro’s hand.

Ramiro waited until he was back in his apartment before inspecting the message. The paper was covered in numbers, far too many to be an address. He stared at it for a while, then went to his console and confirmed his hunch. It had been encrypted with his public key, and the plain text did look like an address.

There was no time specified, but he was loath to delay the meeting or attract attention by trying to get hold of Tarquinia. He tore up the message and erased the plain text from his screen, then set out on his own.

When he knocked on the door, it opened immediately.

‘Are you Giacomo?’ he asked.

‘Yes.’ The man invited him in.

‘Do you think I’m being watched?’ Ramiro had counted at least five cameras along the way.

‘Of course you are,’ Giacomo replied cheerfully, ‘but right now, someone resembling you is being watched in your place.’

‘You sent a decoy into this corridor . . . to be spotted at the next intersection, as if I just carried on walking?’ Ramiro was astonished, though matching the timing to his actual movements would not have been a problem at all.