Outside, the sky was a clear blue-black still dusted by stars, although the sun was already peeking above the flat white horizon. Avatak could feel the chill in his cheeks and nostrils, a dagger-cold that cut and probed, and he wished he’d had time to grease his face. He saw that there had been fresh snow during the night, just a hand’s depth, but enough to cover yesterday’s tracks and to lie on the fur of the huddled dogs. Not much snow – but any snowfall at all at this time of year was an unusual event in Avatak’s short life. Which was, it seemed, why Pyxeas had come here, to the island the Northlanders called Coldland, and for which the People had no name, for it was all the world they knew. He’d come to observe the unusual.

‘At last, sleepyhead! Come, come – it’s on the move, and if we hurry we might witness tremendous events!’ And Pyxeas was off, hurrying east towards the rising sun and the coast.

Avatak had no choice but to follow him. He would much rather have had a chance to check the man over, to see he had his boots on properly and his mittens and a slap of grease on his face, for the scholar had nearly lost a couple of fingers to the frost in his early days by making mistakes like that. But there was no time, no time.

As they hurried through a loose layer of fresh snow, again Avatak heard that tremendous groan coming from the coast, overlaid with cracks and bangs and grinds.

‘Can you hear that? Can you feel it through the ground?’

Avatak thought he could. Pyxeas had taught him how the whole island was covered by an immense lid of ice, all one piece, of which the glaciers were mere extensions. And when the glaciers were on the move the ice cap itself shuddered, shaking the ground on which it rested.

‘Have you brought your pad? Your stylus, eh? No matter, no matter. Watch. Listen. Remember my commentary as I, Pyxeas, interpret what we see. And write it down as soon as you’re home, and make more of those sketches of yours. As soon as you’re home!’

‘Yes, scholar.’

Now they reached the glacier itself. It was a river of ice that poured down from the higher ground towards the sea, where open water lay dark beyond a tide-cracked fringe of pack ice. All this was dimly illuminated in greys and pinks by the dawn sunlight that smeared the eastern horizon. The scholar clambered up onto the glacier’s slick surface, slipped, and would have fallen immediately if Avatak had not grabbed his arm. The man just wouldn’t learn to walk on the ice the way the People did, one foot pressed down flat after the other, slow and steady and safe. After that they went ahead with more caution, pushing down the shallow slope of the glacier towards its termination at the sea. Soon they came to a place where a second glacier joined the first, a mighty tributary whose boundary could be seen in stripes of debris on the surface of the flowing ice.