‘What will you do then?’ Liska asked. She couldn’t imagine how lonely it must be, living on these empty plains with only the wind and a dying tree for company.

Embla shrugged. ‘Die too, I suppose.’ She looked out at the tundra again, squinting at the oncoming hunter. ‘What are those beasts that follow you?’

Liska shuddered at the thought of them, somehow feeling even colder. ‘Seepers,’ she said. ‘Made by the shadow tree. Monsters like that are attacking my city even as we stand here.’

Embla’s broad nose wrinkled in a snarl and her grey eyes flashed as fierce and fiery as her wild hair. She thumped the butt of her spear against the ground and spoke in her own tongue: a guttural mixture of grunts and clicking sounds.

She hates the seepers as much as us, Liska thought. Even though all the shadow trees she could have known were dead generations before she was born. It was an instinct. A loathing that ran through the very cells of those who lived near the sacred trees. And one that Liska might be able to use.

‘Will you help us, Embla?’ she said. ‘Will you help us stop those creatures from killing our tree?’

‘And us,’ Fishbone added. ‘They kill us quite a lot sooner.’

Embla’s hand went to the layers of bone charms at her neck. Liska could see many were carved with pictures and symbols. Perhaps the very last artefacts of her tribe. ‘Nammu is going to die soon,’ she said. ‘If I help you, Nammu dies now. Either way, she dies.’

‘I’m afraid so,’ Liska said.

Embla let out a sigh. A cloud of steam drifted from her mouth, up towards the branches above. ‘But Nammu’s death can help another tree if I give you the heart. And that is what Nammu would want. So take it.’

She bent to the ground and laid her spear at Liska’s feet then stepped aside, head bowed. Liska thought she saw a tear or two fall from the elk girl’s eyes.

‘Before we do anything,’ said Elowen, ‘There might be a chance for Nammu to live on. And you too, Embla, of course. If you are willing to try. Although I cannot promise it will be a success.’

‘What way?’ Embla knuckled the tears from her cheeks and stared at the marble-white face of Elowen. Liska stared too, wondering what she was planning.

‘I don’t know if the elk herders knew the magic, but in other cities there are special people who have joined with their trees. They become another kind of creature, part of both worlds. Treekeepers we call them.’

Embla nodded. ‘There are stories of great elders who walked as wooden gods. Ours died when the walking ice first appeared. We did not know the ceremony to make more.’