‘Not at all,’ Tarquinia said mildly. ‘But I don’t think the politics would work out. If we postponed the launch until your side achieved everything it wanted, then whatever chance the Surveyor had of defusing tensions would vanish.’

‘That’s true.’ Agata glanced back towards the mountain. ‘We’re getting awfully far from the Peerless.’

Tarquinia declined the opportunity to remind her exactly how many orders of magnitude larger her comfort zone needed to be. ‘So do you want to correct our drift and take us back to the slopes?’

‘How?’

Tarquinia detached the tank from her own cooling bag. ‘Incrementally. Small bursts, then wait and observe the effects.’

Agata accepted the tank with her left hand, then brought her arms together behind her back so she could grip it with her right hand as well.

‘You’ll need to hang on to me,’ she told Tarquinia.

‘Right.’ Tarquinia complied. ‘The belt hook alone leaves too much freedom, it’d be asking for trouble.’

Agata said, ‘If we were doing this for real, I’d leave the whole thing up to you.’

‘Pretend I’ve lost consciousness.’

‘In that case I’d cut you loose.’

‘And fly the Surveyor back on your own? Good luck with that.’

Agata closed her front eyes so she could concentrate on the task. She took her time estimating the position of their combined centre of mass, then she aligned the axis of the tank to pass through it while pointing more or less in opposition to the direction in which she believed they were drifting.

She opened the valve, counted one pause, then shut off the air.

The thrust was slightly off-centre, imparting a small amount of spin, but at least she hadn’t lost her grip on the tank. Agata waited until she’d come full circle, then she released a second burst along a shifted axis that largely compensated for the first unwanted torque.

Tarquinia said, ‘See, you’re a natural.’

Agata took a moment to process the remark for traces of sarcasm. She said, ‘There’s only one downside if I get us back safely.’

‘What’s that?’

‘I don’t want anyone believing that they could put their life in my hands.’

‘Because . . . ?’

‘I think we’ll all be much safer,’ Agata explained, ‘if everyone around me is so terrified of the prospect of relying on me in an emergency that they work twice as hard to ensure that it never comes to that.’

Tarquinia said, ‘Don’t worry: there’s nothing you can do to rob me of my healthy respect for the possibility that your incompetence will kill me.’