Eska ran blindly into the twilight, her head full of bears and wolves and cursed anthems. She hadn’t wanted to leave the Labyrinth, even when Flint disappeared into the tent and she was left alone with the Fur Tribe and their mutterings – ‘She’s cursed by the Ice Queen!’ ‘She’s rotten to the core!’ But Eska was no match for Blade and, when he seized her by the arm and marched her towards the ladder, she’d had no choice but to follow.

Now she kept running. Back in Winterfang, she had always dreamed of escaping and finding the tribes. But the Fur people hadn’t been what she was expecting and she felt more alone than ever now. When Blade had grabbed her, she had wanted to call out for Flint whom she had started to think of as a friend, but she hadn’t dared. Because she could see the Fur Tribe were turning against him and Flint didn’t deserve that.

Eska stumbled over a log and crashed down into the snow. She lay there for several seconds, her eyes shining with unshed tears.

An owl hooted, the darkness drew closer and Eska forced herself to her feet. She needed to find some kind of shelter before the light vanished completely. Food would have to wait until the morning.

The shadow of a lynx flitted between the trees and, every time a branch creaked or a twig snapped, Eska flinched. But she kept going until eventually she came to a few slats of wood arranged like a wigwam around a tree trunk. It wasn’t much, but it was enough to hide her until dawn. And so, gathering up a handful of sticks and moss for a fire, Eska crawled inside.

She reached into her pocket and drew out the two splints of metal Inch had stuffed into her palm as Blade pushed her down the ladder. She hadn’t looked to see what they were at the time, though she’d had her suspicions, but as she turned them over in her hand now she felt a lump in her throat. Fire-starters. There had been goodness among the Fur Tribe, but their fear of outsiders was so deep-rooted it meant it wasn’t as easy to spot as she had hoped.

She struck the metal splints against each other again and again, just as Flint had done back in the food store, but nothing happened and, before long, Eska’s fingers felt like rods of ice.

‘Please work,’ she whimpered. ‘Please, please work . . .’

And perhaps somewhere the Sky Gods were listening. Because the flames caught then and, lying on her side in that abandoned shack, Eska watched them flicker until she fell asleep.

She woke to the sound of a sleigh skimming over the snow. Stamping out the embers of the fire, Eska waited. The light coming through the slats showed it was dawn already, but something wasn’t right. Eska listened for the Ice Queen’s anthem, for the voices floating out over the kingdom, but there was nothing. Which could only mean one thing: the Ice Queen wasn’t in her palace. She was on the move.

The sound of the sleigh drew closer and Eska hugged her knees to her chest. It sounded different to the sled that had whisked her away from Winterfang. It was louder against the snow – heavier – and, instead of the patter of husky paws rushing through the trees, Eska could hear the pounding of hooves. Her blood froze. Musk oxen. And only one person rode a sleigh drawn by musk oxen. The Ice Queen.

Eska’s skin chilled. The Fur Tribe would have brushed away her footprints from the Labyrinth the night before, but once a safe distance away from the hideout they would have left them – which meant the Ice Queen could track her. Eska chewed her lip. She couldn’t stay: the Ice Queen had hexed these musk oxen so that they had the strength to run for hours on end. They would find her soon. She had to run, fast, as far as she could.

She lifted back a slat of wood and darted out of the shack into the dazzling sunlight, half running, half stumbling as she pushed through the trees. Her legs were unsteady beneath her and, after a few seconds, a stitch burned in her side, but she forced herself on, one boot in front of the other. She wasn’t going back to Winterfang. Not now. Not ever.

Eska scrambled over fallen trees and skidded on patches of ice, but fear made her blunder on. Then she threw a glance over her shoulder. The Ice Queen’s silver sleigh was there, fifty metres behind, carving a channel through the trees. The queen’s eyes met Eska’s and she smiled through thin blue lips, her teardrop gown billowing behind her. Two Tusk warriors, clad in breastplates of ice armour and holding whips and spears, stood on the sleigh either side of her and, in front, four enormous musk oxen with matted black coats and swooping horns churned up the snow.

‘Stop! In the name of the Ice Queen!’ the guards roared.

Eska dragged her legs on, her heart smashing against her ribcage. She needed the forest to close in, like it had around the Labyrinth, then the Ice Queen’s sleigh wouldn’t be able to force its way through. But the trees here were growing sparser and smaller and, from behind Eska, a whip lashed and the musk oxen ran faster.

Then, to Eska’s horror, the trees stopped. Just like that. And she burst out into the open. In front of her now were the foothills of mountains: rolling valleys that folded in rivers of melting ice and little copses of trees, before eventually climbing up to form the Never Cliffs. The morning sun glittered over the hills and, with a sweeping sense of dread, Eska tried to keep running. But even the slightest incline bit back at her. She didn’t have the stamina for the wild and she knew it.

The sleigh raced closer and Eska whirled round to see the Ice Queen, just metres away, standing in front of her cushioned seat, her staff held high in her hands. Eska grimaced and turned to carry on, but the queen’s words wrapped round her like a snare.

‘You ran away, Eska! Ungrateful child! After everything I did to keep you safe at Winterfang!’

‘Keep me safe?’ Eska panted as she ploughed up the hill. ‘You held me under a curse!’

The moment the words left her mouth, Eska realised her mistake. Fear had made her careless; it had caught her off guard.

‘So you can speak, you little wretch!’ And then the Ice Queen laughed – a bitter laugh that made Eska’s skin crawl.

She ran on, hardly daring to look behind her, then something hard and cold slammed into her back and she was flung, face first, to the ground. Spitting snow and gasping for breath, she looked up. A circle of musk oxen closed in, their heads hung low, their black ice horns glinting in the sunlight.

The Ice Queen held up her staff and the musk oxen stayed where they were, thrashing their horns from side to side, then she stepped off her sleigh, leaving the Tusk guards standing either side of it.

‘I’ve come to take you home,’ she cooed and the musk oxen parted as she stepped into their circle.

She stooped and slid five long white fingers round Eska’s neck. Eska’s pulse drummed at the sight of the red ring on the Ice Queen’s thumb – she’d heard Slither say it was filled with frozen blood – then, quite unexpectedly, there was a scream from one of the guards.

The eagle had come out of nowhere, a golden bullet racing through the sky and ripping the guards’ spears from their hands. The men grappled in the snow for their weapons, but before they could snatch them up the eagle turned and plummeted again, raking its talons across the guards’ faces. The men fell to the ground, clutching their bloodied skin, while the eagle beat its mighty wings up into the sky once more.

Ignoring the guards’ cries, the Ice Queen grabbed Eska by the scruff of her neck and dragged her towards the sleigh. She stamped her staff on to the snow and the musk oxen obeyed, gathering in line before the vehicle.

But the eagle was careering down again, its body tucked in like a barrel. Eska closed her eyes as the bird plunged towards her – she felt sure that it would never stop – but at the very last moment it spread out its wings and in one sweeping arc it dashed the staff from the Ice Queen’s hand, splitting it in two with its talons.

The musk oxen jerked at the ropes that bound them to the sleigh, suddenly waking from the curse that the staff had held over them, and when their ropes snapped, the Ice Queen’s grip on Eska loosened just long enough for her to dart free. She scrambled backwards, hardly noticing that something had slipped from her pocket into the snow, then flung herself into a run. Behind her, the Ice Queen screamed as the musk oxen, no longer under her command, charged off into the forest.

Eska ran at the hill, her ears ringing with the eagle’s high-pitched cries, and only at the top did she allow herself to glance back. The eagle was nowhere to be seen now, but the Ice Queen was bent over the snow and, with a shrill laugh, she picked something up and glared at Eska.

‘I will steal your voice by force!’ she shrieked. ‘When Slither sees what I have here in my hand there will be no stopping his contraption!’

Eska’s insides turned as she dug her own hand into her pocket. The key to the music box was no longer there. And, while she couldn’t possibly know what Slither had created or how the Ice Queen planned to use the key, Eska realised the threat of it all because the queen was stalking off towards the forest, back to Winterfang, with her guards trailing blindly behind her. She could have battled on against the eagle if the bird had returned, but she hadn’t and that fact lay like a cold dark stone inside Eska.

She watched the Ice Queen disappear into the trees, then turned back to the foothills. They rose and fell before her like waves and Eska wondered how anyone could remember their way through when every hill looked just like the last. She sighed, then her eyes fixed on a lone tree a little further down the hill.

And there was the eagle. Perched on a branch like a sentinel.

Eska approached slowly and stopped just a few metres away from the bird. And, as she watched the majestic creature, something like a memory, only looser and less defined, stirred inside her. It was a feeling that although she had no obvious place among Erkenwald’s people she might just have a place among its animals. The feeling lingered for a second longer and then vanished and Eska carried on looking at the eagle.

It was the same one she had freed from the snare before Deeproots. She could see the wound to its left talon, still red and raw from the trap, but that hadn’t stopped it attacking just moments ago. And Flint’s words about it struggling to survive with an injured talon seemed almost ridiculous now.

But, even if Eska hadn’t seen that talon, she would have known the eagle by its eyes: yellow orbs, fierce like the sun. The eagle blinked, then it launched itself off its branch and sailed across the hills until it was nothing more than a speck in the sky, leaving Eska alone once again.