Ramiro was sure now that he’d guessed correctly. Tarquinia had probably worked it out too. It wasn’t something he’d want the whole mountain to know – lest the same deranged killers behind the bombing decided to target the Surveyor itself – but it was always pleasing to be a little less in the dark than his jailers wished.

‘You’d better think up a good cover story,’ he suggested. ‘A new generation of accelerometers, maybe? I’ve been a bit distracted, but other people won’t be so slow.’

Tarquinia was buzzing with mirth; Verano had just explained the way the Surveyor’s toilets would work. Ramiro was unspeakably happy at the thought of having her along on the journey – and if he was trapped now, so be it. He’d wanted to stay strong enough not to back out, and if Tarquinia’s presence would shame him into honouring his commitment that was nothing to lament.

Greta said, ‘All I’ve ever done is work to keep the Peerless safe. I think you can trust me to do the same for the Surveyor.’

‘Perhaps.’ Ramiro couldn’t stop himself goading her when he had the chance, but she’d already proved her resolve to make the mission successful. ‘And I think you can trust me not to flee custody and disappear into some anti-messager safe house.’

‘Perhaps.’ Greta took a key from a pocket in her thigh, then reached over and unlocked the fetter. Ramiro slid the chain free, then eased the bar out of his flesh and let the whole thing clatter to the floor.

He watched Tarquinia haltingly ascend the ladder so she could look down into the Surveyor for herself. Six years to Esilio, six years to come back, then six more if he joined the migration. He’d be at least three dozen and four years old by the time he was walking free across the plains of his new home – and he’d need to outlive the average male in his line by five years to get that far.

He’d managed to constrain his entire future as rigidly as any message encoded in time-reversed light could have done. But if he looked at the alternatives honestly, they were all worse.

16

‘And now you’re dead.’

Agata could no longer see Tarquinia in the whirl of stars and shadow around her, but this flat pronouncement came through the helmet’s link as if the woman were right beside her.

‘I’m sorry.’

‘How did it happen?’ Tarquinia demanded. For a bell and a half she’d been oppressively close, observing every tiny mistake Agata made and dispensing acerbic reprimands, but even the distance this mishap had put between them wasn’t going to silence her.

‘I don’t know! The tank just slipped out of my hands.’

‘Just slipped? Why do you think you’re spinning like that?’

‘I must have opened the valve too soon,’ Agata confessed.