Tarquinia said, ‘I’m not taking any measurements that aren’t essential for navigational purposes.’

Agata doubted she was serious about that. ‘If my real job is to stop Ramiro going crazy and ramming the Peerless, why don’t they choose a pro-messager pilot to keep him in check?’

‘I don’t think they’ve been overwhelmed with applications,’ Tarquinia replied. ‘Anyway, that’s just politics; for practical deterrence, you can bet there’ll be some tamper-proof way to incinerate the Surveyor with the flick of a switch from the Council chambers.’ She squinted at Agata through their faceplates. ‘I’m not going to force you to do anything. If you want to go back to the airlock right now, that’s fine with me.’

Agata was tempted, but she stopped herself. If she pulled out of the training now there’d be no chance to reconsider. ‘Why did you volunteer?’ she asked Tarquinia. ‘Do you think there’d be a war, without the Surveyor?’

Tarquinia didn’t reply immediately. ‘I’m still hoping that we’re not that suicidal, but if we are I wouldn’t pin my hopes on Esilio.’

‘Then why?’

‘Why fly to another world?’ Tarquinia frowned, as if the question were absurd: the mere grandeur of the idea was reason enough.

Agata wasn’t buying it. ‘If it could be easy and safe, then you’re right: who wouldn’t want to be on that mission? But it won’t be.’

Tarquinia said, ‘You want to know what swings it for me? I always thought I was doing something worthwhile just by helping to keep the mountain running smoothly. Given what was at stake for the home world, that was enough. But if the messaging system starts spitting out reports of the reunion, the entire reason for the journey will start to feel like something long past: still worthy, but faded, there to be taken for granted. If I can have a little excitement with a detour of my own – doing no one any harm, and maybe even helping slightly – I’d have to be insane to pass up the chance.’

‘A little excitement?’ Agata would have thought Tarquinia’s encounter with the rogue gnat had given her enough for a lifetime. ‘We’ll be unreachable. If anything goes wrong, there’ll be no one to help us.’

‘Hence . . .’ Tarquinia spread her arms.

‘You think these exercises are going to protect us?’

‘They’ll nudge the odds in our favour,’ Tarquinia insisted. ‘If you ever start taking them seriously. But if you want certainty, feel free to tell Greta that you refuse to fly until they’ve built the messaging system and confirmed the Surveyor’s return.’

‘Would that be so terrible?’ Agata retorted. ‘Or would the whole thing become worthless to you, if you knew you’d be safe?’