Jack strode back into the tent, a ripple of wild applause and music sweeping in behind.

Bianca was waiting for him.

‘How on earth did you get here?’ Jack looked shocked. ‘It’s not possible. Every book is accounted for!’

‘I wrote a new story,’ Bianca replied, unable to keep a hint of pride from her voice. ‘I found your door between the worlds and opened it with words and my imagination. I’ve changed the plot. I am a part of winter’s story. You cannot keep me out.’

‘Congratulations.’ Jack clapped sardonically. ‘But you’re too late. There’s nothing you can do.’ Snowflake hands gestured to the theatre. ‘Their hearts are all but frozen. Now go away. We’ve got a show to put on.’

‘I came here to help you,’ Bianca said, unmoving.

Jack stiffened, looking at her with suspicion.

Bianca drew herself up. ‘There is a flaw in your plan.’

‘Oh, the plan will work,’ Jack insisted.

‘For this winter.’ Bianca nodded. ‘Perhaps the next one. But for how long?’ She paused, knowing it must be a question Jack had pondered. ‘Can the frozen hearts of two hundred children keep Ishild alive indefinitely, when the planet is getting warmer all the time?’

‘It will stop her from dying now.’ Jack’s voice cracked, and Bianca could hear the fear and grief.

‘For now,’ Bianca said softly, ‘but then what will you do?’

Jack didn’t reply, instead going to the mirror framed with light bulbs and removing his white top hat.

‘You’ll never be able to make enough silver books to sustain Ishild forever,’ Bianca said, taking a step closer. ‘You must know that?’

‘Every time this planet cycles round the sun, Ishild is diminished.’ Jack’s head drooped and Bianca could see the toll this fight for winter was taking. ‘I am the frost that lives in the liminal shift between autumn and winter, winter and spring.’ Jack gave a half-hearted theatrical hand wave. ‘I am the Snow Queen’s herald. I go before her, announcing her arrival. When she no longer graces the Earth, neither will I.’

‘None of us want that, Jack.’ Bianca moved nearer, wishing she could reach out, but knowing she couldn’t touch the frosty figure. ‘The Earth needs winter.’

‘Ha!’ Jack’s head snapped back angrily. ‘Your factories belching hot gas into the sky tell a different story. Humans are burning this planet, heating it by degrees, driving us out.’ Jack’s lips curled into a sneer, showing a glimpse of needle teeth. ‘Look at the melting glaciers and the shrinking ice plains.’

‘But you must know how wonderful we think winter is,’ Bianca countered. ‘You saw it when you created Winterton for us.’

‘I know how wonderful children think winter is,’ Jack conceded. ‘They see the joy and beauty of it. They don’t fear the cold. That is why we made the silver books for them – and them alone. They are willing to make a sacrifice. Many fully grown humans are no longer close to nature. They would not consider it.’

‘It’s like that fairy story about the selfish giant,’ Bianca said, nodding. ‘Except humans are the selfish giant that won’t let others play in our garden.’

‘The Earth, contrary to what you believe, is not your garden,’ Jack snapped.

‘You’re right,’ Bianca said softly. ‘I was thinking of a story.’

‘I know the one.’ Jack nodded.

‘It was Ishild’s riddle that helped me understand how you are freezing our hearts,’ Bianca explained. ‘The mirror splinters you put in the silver books, they’re from her story, aren’t they? The story of The Snow Queen.’

‘When I used to visit your houses to paint frost ferns on your windows, after dark, I would listen to the bedtime stories parents read their children,’ murmured Jack. ‘I’ve heard many tales over thousands of years. My favourites were the wintry ones.’

‘Is that how you heard The Snow Queen?’

‘Yes. The tale told of a magic mirror, created by a devil to play a trick on the angels. It reflected beautiful and good things as ugly and evil. You could be eating delicious ice cream, but looking in the mirror would make it appear and taste like dog poop.’ Jack chuckled. ‘When the mirror was finished, the devil sent it to the angels, hoping they would look in it and see themselves as horrible. But the mirror slipped from his servant’s grasp and fell to Earth, shattering into a million pieces. Some of the tiniest pieces got lodged in people’s eyes, and they saw the world as a grim place.’

‘And some people got splinters in their hearts, and their hearts became lumps of ice,’ Bianca finished. ‘But the mirror isn’t real. It’s from a story.’

‘What is real? Is Winterton real?’ Jack raised an eyebrow. ‘I looked into the hearts of the heartless. I found shards of that mirror. I’ve been collecting them for more than a hundred years. Ever since the Arctic started warming.’ Though Jack’s eyes were blank, Bianca read sadness there. ‘You saw my sister in Snow Haven. She is weak. I have no other way to make her strong. I will not let Ishild die.’ A snowflake hand gestured to Winterton. ‘This is not cruel. The children have forgotten their past lives. They are happy. Their winter spirit animal is made flesh, so they have a best friend to play with.’

‘Winter spirit animal?’

‘Yes. Inside the soul of every human are the spirits of four creatures that express your connection to each season. They are a part of you. Winterton makes your winter spirit animal flesh. It’s part of the magic of this place.’

Pordis! thought Bianca. You are my winter! And she smiled, knowing it was true.

‘Jack. What will happen at midnight on the winter solstice?’ Bianca asked.

‘The children will willingly give their frozen hearts to Ishild. They will die in the real world, but they will live on in Winterton forever.’

‘Never growing or getting older?’ Bianca tried to hide her horror, as thoughts of her grieving parents filled her head.

‘They will be ice figments,’ Jack replied. ‘Elemental creatures of winter, like me.’

‘Jack, I want to help you save winter, I really do,’ Bianca insisted. ‘But this isn’t the way.’

‘You do not want to help me. You are here for yourself, to take back your brother from Ishild.’

‘You’re wrong, Jack,’ Bianca said, desperate to explain what she knew to be true. ‘I’m scared of the planet getting warmer. If the climate changes and the polar ice caps melt, seas will rise and the world won’t be safe for any of us.’

The music from the circus stage ended. Bianca’s heartbeat accelerated as she heard delighted howls, cheers and the clatter of footsteps, mixed with applause.

‘Then you understand why I must do this.’ Jack stepped towards the door of the tent.

‘No.’ Bianca moved to block the doorway.

A white eyebrow lifted.

‘Taking their hearts tonight won’t save winter forever.’

‘There is no other way,’ said Jack.

‘But there is,’ Bianca insisted. ‘You have to listen to me. Children are powerful. We are the future grown-ups. The people we decide to become, the things we choose to do with our lives – that will change the world.’ She looked at the immobile features of Jack’s thin face, hoping to see her words sinking in. ‘To save winter, we need to change the hearts of the whole human race. You can’t do that by freezing the hearts of children. It will make adults want to destroy winter. It will start a war.’

Jack’s lips formed a stubborn line. ‘If it’s a war they want, then so be it.’

‘No! Jack! Ishild’s riddle was right. Stories can change the world. They change the future by changing the minds and the hearts of people who read and hear them. They are powerful enchantments. And those who listen and read best, most wholeheartedly, are children . . .’

‘You’re stalling, to try and save your brother,’ Jack snarled, pushing past her, and throwing back the tent flap. Bianca saw a ripple of green and purple light in the dark sky behind him. ‘The aurora borealis is dancing. The heart-giving ceremony is almost upon us.’

‘You must listen to me, Jack.’ Bianca grabbed the figure of Frost, gasping as her hands turned to ice, but not letting go. ‘There is only one way to save winter, and that is to make all humans love it, see the importance of it, the sacredness of it. We have winter spirit animals because we are a part of winter and winter is a part of us.’ Her impassioned words came from the very centre of her soul and rang with truth. ‘If you take our hearts, you will be turning winter into a villain. Something to be beaten, thwarted and extinguished. You’ll be turning your wonderful sister into an evil queen who steals children’s hearts and eats them. Do you want those to be the bedtime stories you hear at windows?’ she cried. ‘Don’t you see? We must come up with a better ending.’

‘Enough!’ Jack broke free of her grip, knocking Bianca to the ground, and strode out of the tent. ‘It’s too late.’