Ramiro waited for this revelation to bring him clarity, but it was no help at all. He could believe that, in the end, he would decide that the bombing was the lesser of two evils compared with a meteor strike. But if he’d heard the opposite claim he would have concluded that he’d convince himself that with the saboteurs left weaponless, the Council would step in and do the deed themselves. Neither answer would have rung so false as to convince him that it couldn’t be true.

‘What do you think we should do?’ he asked Agata.

She said, ‘I’m going to find a way to shut down the system without blowing anything up.’

‘How?’

Agata hummed disdainfully. ‘Do you seriously expect me to have the answer already?’

Tarquinia said, ‘Not how to shut it down, but how to find a way.’

‘The innovation block isn’t an absolute principle.’ Agata was defiant. ‘Maybe in the long term it’s impossible to keep anything secret – but the closer we get to the disruption, the easier it should be to keep my ideas to myself until it’s impossible for them to leak into the past.’

Ramiro said, ‘And the closer you get to the disruption, the less time you’ll have to come up with something workable and put it into practice. That’s a slender thread on which to hang the fate of the mountain.’

‘Perhaps,’ Agata conceded. ‘But why did the ancestors send me that message, if not to give me the courage to try? They couldn’t tell me what the method would be, but they could strengthen my resolve to find one.’

‘You think the ancestors were speaking to you personally?’ Ramiro glanced at Tarquinia, wondering if she’d finally break her silence and admit to the forgery.

‘When the rock face was exposed,’ Agata replied, ‘I didn’t think the message was for me at all. I didn’t think I needed it. But the ancestors won’t choose that site lightly. They’ll know our whole history, they’ll know how all the pieces of it fit together. They’ll know exactly how and why we came through this unscathed. If the disruption had a natural cause, why wouldn’t they simply tell us that? It’s the fact that they can’t reveal the details that reveals the nature of the event.’

Ramiro wasn’t sure how much his own face was revealing. ‘Go ahead, then,’ he urged her. ’See what you can come up with.’ It couldn’t do any harm.

‘That’s not enough,’ Agata said. ‘I’m going to need something from you, or I’ll be wasting my time.’

‘What do you need?’