Eska trudged on through the foothills, squinting into the glaring sun. The snow was melting in places with patches of grass, juniper and rocks poking out and once or twice she jumped as a chunk of snow crunched away from the hillside, then slid down into a hollow. She climbed up on to a ridge. She needed to find shelter, a place to hide should the Ice Queen return, but she was thirsty and hungry and her legs were close to buckling. She picked up a handful of snow and sucked on it, but it tasted stale, like animal sweat, and she spat it back out.

Eska looked out at the landscape before her. There wasn’t a living soul in any direction – just the curved backs of the foothills. She sighed. This was a vast and silent emptiness that she knew nothing about. She thought of what Flint might do. He moved quickly, thought quickly and spoke quickly, but Eska did none of those things. She felt tears prick the back of her eyes as she remembered his words to her on the sled: You don’t even know anything. And he was right. Flint was a part of the wilderness – he understood it – but, as Eska gazed upon it, she felt that it could swallow her whole.

She sat down on a rock, pulled her hood up against the wind and closed her eyes. She was an outcast whichever way she turned. And yet there had been that moment with the eagle on the hillside; somehow things had felt, for a fleeting second, almost familiar.

Eska’s eyes sprang open as a noise – a high-pitched cry – sounded from further across the hills.

The cry came again, splitting through the wind, but when Eska threw back her hood she saw only snow-covered hills. She scrunched up her eyes and scanned the foothills and it was then she saw the eagle gliding above the ridges, a dark streak against the deep blue sky.

Eska watched the bird for a few seconds. Perhaps it was hunting for mice or marmots – Flint had said as much back on his sled – but, as she looked on, Eska began to wonder whether that was really what the eagle was doing. It didn’t dive down to catch any prey, but it didn’t sail off into the distance either. It just soared between the hills, back and forth, back and forth, as if – maybe – it was waiting for something.

Eska looked around. Perhaps it was waiting for another eagle. But no more birds appeared and, as the eagle cried again, Eska thought of Flint’s words: There’s a bond between animals and tribes out here. Her breath fluttered. Was the eagle helping her in return for saving it from the trap? Eska stood up and, because she had no bond with any person or any place, she found herself walking over the hills after the eagle.

She was hungry still and her legs ached more than ever, but something about the bird made her want to follow it and, as Eska crested yet another hill, her heart leapt. Before her lay a valley and in it was a wide, meandering river folded in on both sides by hills. There was a small forest wrapped round one of the hills to her left and beyond, where the river narrowed further up the valley into a ravine, she saw the landscape rise into jagged peaks. The start of the Never Cliffs, possibly, where Flint had said the Feather Tribe lay hidden. Maybe they would offer her protection. Maybe they would be more welcoming than the Fur Tribe and she’d be able to find a way to work with them to defeat the Ice Queen . . . It wasn’t much of a plan, but it was all she had, though if she was going to make the journey to find them she’d need to learn to hunt and build shelters first.

Eska skidded down the hillside, boots slipping on loose stones and snow, until she came to the river. She knelt beside it, cupping hands into the water where the ice had melted, and gulped the liquid down. It was cool and fresh, like drinking the wind, and when the ripples stilled Eska saw all the red, greens and blues of the rocks on the riverbed. Suddenly the landscape didn’t seem as white and as bare as it had done before. The eagle cried above her again. She had been following it for at least an hour now and it seemed to do that every time she stopped to catch her breath – and Eska couldn’t help feeling, or hoping, that it was trying to lead her somewhere.

She walked on through the valley beside the river, keeping the eagle in her sights as it flew ahead, and, just when she felt that she couldn’t possibly drag her legs on any further, the eagle landed on a rocky ledge leaning out over the river.

Eska blinked. She had been looking up at the eagle for so long that she had missed what had happened to the river. Before her was a waterfall, shielded on either side by crags and rowan trees, only the water itself hadn’t melted up here. It was locked in ice still: a great white curtain built of icicles that hung in spiked ropes.

Eska thought of the organ in Winterfang. The icicles that formed that instrument had been conjured by dark magic – and every day she had trembled at the sight of them – but, though these were just as fierce and splendid, they did not bend to another’s power. They were wild and gazing at them now Eska wondered whether she had found something as powerful as the Ice Queen.

She glanced up at the eagle, expecting it to fly away. But it simply sat, its eyes fixed on the waterfall level with its perch. Eska looked again, at the rocks either side, capped with polished ice, and at the jagged blue tips of the icicles hanging down. It was so quiet, this waterfall, but Eska sensed it was only holding its breath. One day soon, as the days stretched out and the melting began, it would roar. And, as she was thinking of the rush and pound of water to come, she found herself squinting at the frozen spirals, looking deeper, harder, than she had before. She clambered on to the rocks, aware of the eagle watching her every move, and her heart skipped a beat.

There was a tiny gap between the icicles in the waterfall and, behind that, Eska could see wood, not rock as she had expected. She edged still closer, her eyes glued to the ice, then suddenly the eagle squawked from its ledge and Eska looked down. She was only centimetres away from a sheer drop down to the river.

Carefully, Eska climbed over the rocks until they spread out into a platform beneath the eagle’s perch. The waterfall hung like a veil in front of her and she noticed the rocky plinth she stood on extended right under it and that there was an opening in the ice large enough for a person to squeeze through. Eska could no longer see the eagle above her, but she could feel it watching, waiting, so she crept over the stone platform before ducking behind the ice.

Her eyes widened. On her left hung the waterfall, a silent shield, but on her right there was a small wooden door built into the rock face. Eska blinked. Did somebody live behind this waterfall, tucked out of sight from the rest of the world? Was it safe for her to stay? She thought of the Ice Queen and Slither brewing curses to snatch her voice – she needed shelter from their dark magic and this place was about as secret as shelters could come.

She stretched out her hand and knocked on the door. Silence. She knocked again, a little louder this time, but still no one answered. And then Eska reached for the handle, a piece of wood carved into a half-moon, and turned it.

The door creaked open and, as the light spilled in, a smile spread across Eska’s face. Nestled into the rocky chamber in front of her there was a table laden with wooden bowls and spoons and boxed in by several chairs. There was a stove cut into the rock, too, and beyond that two beds draped with furs. Eska gasped. Someone had even chiselled a little tunnel into the right-hand side of the rock and a pane of glass had been fitted at the end. Eska wondered whether she might be able to see the eagle perched on its ledge from there, then her gaze fell to the item leaning against the tunnel wall. The best thing of all. A spear.

‘I can hunt now,’ Eska murmured. ‘There’ll be fish in the river – and probably bears around, too.’ She paused. ‘Though I’m not sure I’m quite ready to tackle them.’

She grinned. This had to be one of the food stores scattered over Erkenwald that Flint had mentioned. Somehow the eagle had led her right to it and, though Eska’s mind was spinning with the discovery, she didn’t rush inside right away. She crept back to the opening in the ice and looked up at the eagle on its ledge.

‘Thank you,’ she whispered.

Then she looked down at her feet and sighed. She was glad of the hideaway and all that it meant, but she was also sorry that now the eagle had repaid her favour she might not see it again. Eska’s heart was filled with longing – for family, friends and a home that she remembered – but a little space inside it had opened up for the eagle and, as she dipped her head before the bird now, she hoped that it understood.

The eagle ruffled its feathers, but it didn’t fly away. It just croaked, an impatient noise, as if it was eager for Eska to go inside.

She smiled. ‘All right, all right. I’m going.’

She turned back beneath the waterfall, stepping inside the hideaway and closing the door softly behind her. Then she flopped on to one of the beds, shutting her eyes against the sunlight streaming in from under the door. She knew she should take the spear down to the river – it was past midday and she had to eat – but the furs were so soft around her that, within minutes, she was fast asleep.

When Eska woke, the hideaway was dark and cold. She sat up on the bed and her stomach growled.

‘I should have gone fishing while it was light,’ she muttered, scrambling out of bed and feeling her way down the little tunnel to the window.

She pushed the sack curtains aside and a strip of moonlight fell across the hideaway. Eska pressed her face up against the glass and looked out.

‘Please be there,’ she whispered.

But the stone ledge the eagle had been perched on was silhouetted against the moonlight – and it was empty. Eska turned away. Of course the bird wasn’t there. It had repaid the debt and now it had left. Those were the ways of the wild.

‘Hunt,’ Eska said to herself. ‘You need food. Then a fire.’

For a moment, her mind wandered towards the next day, and the day after that. What was she doing, really? What was her plan? Find the Feather Tribe when not even the Ice Queen, with all her dark magic, could root them out? Use her voice to free the prisoners at Winterfang when she didn’t even understand its power and she knew the Ice Queen now had plans to steal it from afar?

Eska looked around her. Inside the hideaway she felt relatively safe, but she’d have to go out soon – to hunt, to get water and then on to find the Feather Tribe – and she’d be completely and utterly alone. The tasks ahead loomed large, but after a few minutes Eska shook herself.

‘There’s no time for that kind of thinking. I need to work out how to survive out here first. Then I can think about what happens next.’

She grabbed the spear. It had been carved from caribou antler and the end was tipped with a slice of flint bound with animal sinew. Gripping it hard, she opened the door.

And screamed.

There was a dark, round shape just in front of her on the rocks. For a second, Eska was rooted to the ground with fear and then the shape hissed and grew as two large wings flapped open and the eagle hurried to the opening in the waterfall before launching up into the sky. It landed, seconds later, on its ledge and Eska breathed out and laughed.

‘You scared me,’ she said as she crouched in the opening between the rock and the waterfall. And then Eska was silent for a moment as she realised that the eagle wasn’t just perched on a slab of stone. There was a large bundle of sticks on that ledge and the bird was settled inside them. Eska gasped. Those sticks were a nest. This was the eagle’s home.

‘I thought you’d gone,’ Eska said. ‘Most people seem to take off after they’ve met me.’

The eagle yapped as if to disagree, then it shifted its weight. Eska watched. The bird was trying to tell her something – she could feel it – but she couldn’t read its sounds and signals. Then she happened to look behind her, at where the eagle had been when she opened the hideaway door, and there, laid out on the rock, was a bird as white as milk.

‘A ptarmigan,’ Eska breathed.

And then she blinked in surprise. The bird’s name had come to her just like that – as if she’d always known it – and somehow she knew instinctively that she could use the ptarmigan’s feathers to fletch arrows before roasting its meat. Eska stayed very still. Were these memories stirring? Fragments of her past hovering closer? But, when several minutes passed and nothing more came to her, Eska picked up the bird and glanced at the eagle.

‘You caught this for me, didn’t you?’

The eagle yapped again and Eska dipped her head. Hunting for fish could start tomorrow because now she had food and shelter for the night. She stole back inside the hideaway and lit the stove – and, though there was an Ice Queen set on stealing her voice and a wilderness beyond the waterfall that seemed to shake the night air, Eska smiled.

She wasn’t alone now. She had an eagle – a friend – on her side.