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.’