Pyxeas sighed. ‘It was a difficult decision to make. Of course it is difficult. The suffering that will follow from this act, the thousands that will die. I – we, for the other Northlander elders in exile concurred – we are playing games on a continental scale. But we have to be rid of the Hatti, you know. There isn’t room for them here, especially not if we are to build our own city, a New Etxelur. Sharing Africa with the Carthaginians will be bad enough. And then there is Mali, south of the desert, rich from its gold mines, which has been relatively spared by the longwinter so far. Now the mansa is making what some regard as aggressive noises towards its northern neighbours. We have enough to handle here. Let the People of the Jaguar deal with the Hatti.’

‘I can’t believe you will give away precious Northlander lore.’

‘But the Hatti would probably soon steal it anyway. And besides, the fire drug knowledge is nothing. A shiny bauble, a whiz-bang toy that distracts small minds, like those of princes and generals. Once, you know, the great treasure of Northland was flint, a particularly fine lode that was mined from Etxelur. That was what men crossed the world for! Now nobody cares for flint at all. But since the age of Ana our true treasure has been Northland’s deep and ancient collective memory, our profound understanding of the world and its cycles – even as those cycles scatter us across the globe. Which is why I must return to Northland, by the way.’

‘What?’ Nelo stopped and stared at him. ‘Uncle, are you mad? The weather was bad enough last year when I travelled down with my mother. It may not even be possible to make the return journey now. Your journey to Cathay nearly killed you!’

‘Ah, but I live on.’

‘Now you want to do it again?’

‘I must, Nephew. I brought back much lore from Cathay. I have since reached certain conclusions . . . I must consult any scholarship that survives at Etxelur, and I must reach the Wall Archive before it is lost to the ice altogether. For we must build an Archive in New Etxelur, wherever it is founded, and we must stock it with the heritage of the past. To preserve the idea of Northland, and our learning and scholarship.’

Snow swirled down, thicker, heavy flakes that beat like chill butterflies against their faces. They walked on, side by side.

‘I will come with you,’ Nelo said impulsively.

Pyxeas studied him. ‘Are you sure? I have Avatak.’

‘He is a good man. He will be better with me at his side. There is nothing for me here.’

Pyxeas, limping as he climbed, clapped Nelo on the shoulder. ‘Very well. But make sure you secure your drawings first. They must be preserved too. That mad Roman was right, that they are a true first-hand record of the last war in history . . .’