But Nelo said, ‘I thought he was trying to teach you. I know he’s come up with some big idea about why the longwinter is happening.’

‘Yes. We were on a ship when he said he got it, the final solution. Pirates were smashing in our heads at the time.’

‘Didn’t he tell you?’

‘I stopped listening. It’s all—’ he searched for the word ‘—abstract.’ He found he’d used a Cathay word. He tried again. ‘Not real. Not here and now. Once his learning interested me. In Coldland, there’s nobody like him. But we barely survived that journey from Cathay, and now this. What does it matter what this country will be like in a thousand years from now? Somebody else might be trying to cross it then; it won’t be us.’

‘True enough, my friend,’ said Himil.

Nelo asked, ‘Then why did you stay with my uncle?’

Avatak looked at the old man. ‘For what’s inside him. Not his knowledge, all those numbers. Which is all he thinks there is to him.’

‘What then?’

‘His sadness. At what he saw before anybody else saw it, before a single flake of snow had fallen. Sadness for the world, and all of us who must live in it. Even the generations to come. That’s why I stay with him.’

Nelo considered this. ‘You’re a good man, my friend.’

Avatak shrugged.

They followed the river upstream, travelling roughly north-west for some days, until they came to another large city, far inland. They left the boat here; it returned to the coast, taking the soldiers with it, and they were on their own.

This city was a mere shadow of what it must once have been. It had extensive walls, breached, burned and roughly repaired. Inside the walls whole suburbs looked abandoned, burned out. The country beyond seemed empty, with only a tracery of the walls of abandoned farms to be seen. Avatak wondered, in fact, how the city kept functioning at all.

‘And no dogs,’ Himil said. ‘Have you noticed that? No barking. And no cats. Or cage birds singing.’

‘All long gone into the pot,’ Nelo said gloomily.

There may have been no dogs, but there were horses to be had, scrawny nags at a price that Himil the Carthaginian said was eye-watering. But Avatak knew their money did not matter; it would count for nothing once they got further north, and may as well be spent while there was something useful to buy.