‘Yes, I believe so,’ said Elowen. ‘I heard tales of a tree to the east whose people had found a way to destroy their shadow tree using magic. And of a place to the west where evil won, and the tree of light was devoured. Legends, probably, but there is often a grain of truth in them.’

Liska looked at the bumps and ditches on the ground, covered over now by grass and moss. She tried to imagine a sea of tents and log buildings here, the spaces in between filled with bustling people. Shapewalkers maybe, just like her. A whole city full of stories – of families, friends, enemies – that had sat here for many years, centuries even, and was now just . . . gone.

She imagined how Nammu would see it, in the slow, creaking life of a sacred tree. The rise and fall of cities would probably just be a blink to Nammu. One day there was nothing, then a horde of swarming humans and then . . .

. . . back to emptiness again – apart from a single girl with her spear.

Who was still watching them. Very closely.

Liska stared back as they stumbled nearer. She was young – perhaps close in age to Liska herself – but she was much stockier, with broad, muscled shoulders and thick arms and legs. She wore clothes of stitched leather, necklaces of bones and beads. Her eyes looked grey from this distance. They stared out from beneath a heavy jutting brow and either side of a wide flat nose. Her mouth was broad too and set in a stern line, jaw clenched. Traces of blue paint striped her cheeks, and her cloud of red tangled hair whipped back and forth in the wind, looking like a halo of fire raging around her shoulders.

They staggered the last few steps, in between the frosty roots of Nammu. Now the face of the glacier could be seen clearly, especially the part that surrounded the tree. The ice here was clear and fresh, marked all over with chips and slices.

Carved. Liska realised. Someone has carved the glacier away from Nammu. They have stopped it from being frozen.

She looked closer, spotting wooden scaffolding that ran up the glacier face. Stone tools – picks and axes – were resting up against it. Liska let out a whistle. How much effort must it take to cut away a glacier? How much sheer stubbornness to take on the most powerful force in nature? And to be done by just one girl?

Who was now looking down, probably just about to introduce them to the pointy end of her spear.

‘Erm . . . hello?’ Liska said.

The girl tilted her head to one side, sizing up the newcomers. She seemed particularly interested in Fishbone, who had made his eyes look as innocent and adorable as possible. He blinked them a few times for added cuteness.

‘What do you want?’ the girl said. Her voice was deep and gravelly, her accent thick, but they could understand her words.