Azelio knelt down and continued his inspection; Agata did the same. As she turned the revelation over in her mind, she was surprised at her own equanimity. After six years away from the mountain the conflict that they’d come here to remedy seemed remote and petty. If they really could rid the Peerless of Medoro’s killers by showing that a settlement was viable, she’d certainly relish that victory – but between the light-deflection measurements and her work on the vacuum, she already found it impossible to think of her time here as wasted.

But Azelio had no such consolations; he was only here in the hope of making the mountain safer for the children he’d promised to protect.

On their way to the next plot Agata asked him, ‘Is it the composition of the soil? Or is it the arrow?’

‘I can’t say for sure,’ Azelio replied.

‘Can’t you guess?’ Agata pressed him.

He said, ‘The spectra suggest that at least two of the soil types should have had everything the wheat needed.’

‘So it probably is the arrow?’ There was nothing inimical to life about the mere presence of a conflicting arrow; the crew had survived it perfectly well, thanks to their store of food with its unambiguous origins and their undiminished ability to rid their bodies of excess heat. Esilio even accepted their excrement without complaint, however bizarre the material’s fate would seem to a time-reversed observer. But the plants’ uptake of nutrients relied on interactions between their roots and the native soil at a microscopic level, and there was no guarantee that the two systems, left to themselves, would simply sort out their differences.

Azelio wasn’t ready to give up hope of a simple agronomic solution. ‘We could try mixing the most promising soils,’ he said. ‘Or we could look for better conditions elsewhere. If it’s the arrow, that’s the end of it.’

Agata said, ‘I’ll defer to your expertise on soil chemistry – but when it comes to the arrow, let me be the judge. The problem still might not be insurmountable.’

‘Really?’ Azelio buzzed sceptically. ‘You can’t even sweep your own floor any more. How are you going to reach into the ground and persuade every speck of dust that it’s mistaken about the route it’s taking away from the entropy minimum?’

Agata had no answer to that. But if she couldn’t change the brute facts, the cosmos wasn’t taking sides in this clash: it simply had no choice but to reconcile everything it had brought together. If there had to be an accommodation between Esilio’s arrow and the Surveyor’s, the trick would be to find a way to make the crop’s failure even more improbable than its success.