Two hours later, the moon rose and in the distance its pure pale light fell on the leading edge of a white plain. The meeting of grey, damaged earth and white earth was striking not only for its extreme contrast but because they met in a line that was unnaturally straight. It was impossible to imagine that whatever had befallen these lands had not been of human doing, for nature did not cut its cloth so neat.

Analivia had begun to describe it to Dameon, but when she spoke of the whiteness as a plain, Ahmedri said flatly, ‘It is not a plain.’ He pointed away to the horizon. ‘Those are dunes. It is a desert.’

I squinted and could not see anything other than whiteness, but I did not doubt he had seen what he said, for a Sadorian would know very well what dunes looked like.

‘Look there,’ Swallow said, pointing to a large body of water shining silver in the moonlight at the margin of Blacklands and white desert. The pool was wide at one end and narrowed at the other like a tear. At the wide end of the lake there was a large outcropping of black rocks. I did not see how this could be the clean water Rheagor had mentioned, since it was surrounded on one side by tainted ground, but there was no other water in sight and Rheagor turned to the south-east to make directly for it. It was not until we were quite close that I saw the narrow end of the pool gave forth a thin stream that went meandering away to the south along a deep narrow channel that ran precisely along the border between the barren grey-black terrain that was the end of the Blacklands and the white plain. This suggested that the pool was formed about a spring, which was gradually running away in a stream.

From a distance, I had not seen steam coming off the surface of the pool, but when we were closer I noticed there was water welling from the top of the mound of stones at the northern end, and running down it into great flat boulders that appeared to have been sculpted by the flow into natural bowls. From these, water spilled into the pool, which was truly large enough to be called a small lake. A veil of steam hung above the brimming stone bowls, but not above the lake, whose surface would have been like a silver mirror in the still night, save for widening ripples emanating from where the spring water entered it.