How many heartbeats does Finn have left in the real world? Bianca thought as she ran out of the tent, her frozen hands slowly thawing. Jack had vanished. Cursing, she hurried to the stage and lifted the woven backdrop.

All the children in the theatre had their mouths open and were looking up. Pitter and Patter were performing a death-defying trapeze routine, flinging each other into the air and catching one another as their swings rocketed forwards and backwards. She saw Pitter hurled upwards by Patter. He pretended to swim through the air, hovering, defying gravity for an impossible moment as the sky above him glowed with the soft, shifting colours of the Northern Lights. And then he fell into a tumble, roly-polying towards the ground. Patter swung down and grabbed his feet when he was barely a metre from the icy stage.

The children roared their approval, leaping to their feet and applauding.

‘Pordis, I need you,’ Bianca whispered, crawling under the cloth. Getting to her feet, she immediately felt vulnerable, standing at the back of the huge stage. Everyone could see her.

‘I am coming,’ Pordis replied.

Standing there, Bianca’s heartbeat accelerated. She felt impossibly small, searching the crowd for familiar faces. Where had Jack gone? She didn’t know what she was going to do, but she knew she had to do something to change the ending of Jack’s story. She immediately felt braver when she saw Pordis, her winter spirit animal, leap onto the stage. The reindeer trotted over to her.

‘I am here.’

Two grey figures dropped from the sky, landing in front of Bianca and Pordis, barring their way.

‘Where d’you think you’re going?’ Patter asked snarkily.

‘What seeds are you sowing?’ Pitter leered at her.

Bianca gave them her most innocent smile. ‘I’m here to see you dance. My brother says that when you do, hail and sleet fall from the skies, and that it’s one of the most awesome sights in the world.’

Pitter and Patter both seemed to grow taller.

‘Your brother is right.’

‘Our dancing is a sight . . .’

‘. . . that you must behold . . .’

‘. . . before you grow old!’

And the pair tapped a slow, sharp beat with their right feet on the icy floor of the stage.

The audience fell silent with anticipation, and Pitter and Patter couldn’t resist turning to face them. They hopped with a skip, jump, tip, tap, forward and back, to the middle of the stage.

The children started to clap in time.

Pitter and Patter chanted a poem as they danced.

‘Come –’ tippety-tap – ‘winter –’ tip-tap – ‘come . . .’ Skippety-snap.

‘. . . with –’ tippety-tap – ‘dazzling –’ tip-tap – ‘low sun.’ Skippety-snap.

A barrage of hailstones fell from the skies in a neat circle around them, landing on the stage and creating a soft rhythmic accompaniment. The audience murmured with wonder at this neat trick.

‘Decorate branches and bowers . . .’

‘. . . with crystalline flowers.’

Skippety-snap, tap-tap.

‘Creep –’ tippety-tap – ‘frost –’ tip-tap – ‘creep . . .’ Skippety-snap.

‘. . . while –’ tippety-tap – ‘we –’ tip-tap – ‘all sleep.’ Skippety-snap.

‘Your breath becomes mist . . .’

‘. . . when the earth is frost-kissed.’

Skippety-snap, tap-tap.

‘Fall –’ tippety-tap – ‘snow –’ tip-tap – ‘fall . . .’ Skippety-snap.

‘Blanket –’ tippety-tap – ‘us –’ tip-tap – ‘all.’ Skippety-snap.

‘Silence life’s thrum . . .’

‘. . . its buzz, tweet and hum.’

Skippety-snap, tap. Tippety-tap, tap.

Crat-tickity, ga-ga-skippety – ‘HA!’ they both cried, their arms above their heads, hailstones and sleet flying from their fingertips and raining down on the stage.

The audience exploded into rapturous applause.

Bianca didn’t give herself time to think. She put her hand on Pordis’s neck and marched into the middle of the stage. It was now or never.

‘Are you ready to meet Her Majesty, Ishild, the Queen of Snow?’ Bianca cried, not certain what words might fly out of her mouth. Her body was trembling, and she leaned against Pordis for support. She spotted Casper as he leaped in the air and shouted ‘YES!’, beginning a response that rippled around the theatre. He was in the front row to her right.

Pitter and Patter looked at Bianca with confused expressions. They hadn’t expected her to say that.

Lifting her chin, Bianca pronounced in a loud clear voice, ‘There once was a time of great harmony,’ and Winterton seemed to vibrate as if a giant string had been plucked. ‘And we are the Ice Children, destined to bring about a time like that again! AREN’T WE?’

There was a roar of approval from the audience.

From the corner of her eye, Bianca could see Pitter and Patter quarrelling. Pitter pointed two fingers at his sister and shot a ball of hail at her in frustration. Patter opened her mouth and shot a stream of sleet into his face.

‘Behind this very stage, the Snow Queen is waiting to meet you all,’ continued Bianca putting her hand to her ear. ‘Are you excited?’

There was a loud cheer of ‘Yes!’

‘I can’t hear you!’

‘YES!’ screamed the children.

‘Who here loves snow?’ Bianca cried, finding her stride.

‘ME!’ shouted Casper.

‘I do!’ Gwen put a hand in the air.

‘I like it best!’ cried Sophie Lilley.

‘Who loves ice cream and slushy drinks?’ Bianca asked. ‘Hot chocolate and holidays? Festivities and singing carols?’ She fired out the questions without leaving any gaps for answers. ‘Who loves skiing and snowboarding? Ice skating? Snowball fights, sledging, snow angels and snowmen?’ She paused. ‘Who loves WINTER?’

She’d worked them up into a frenzy. The children were all on their feet now, jumping about, screaming and shouting. Polar bears were clapping. Penguin flippers were flapping. And the aurora borealis came in waves of emerald and magenta light above their heads.

‘But tonight –’ Bianca raised her hands – ‘may be the last time you ever get to see the Snow Queen.’

The clamour immediately dropped to a concerned chatter.

‘Because winter is in trouble, my friends. It needs our help.’

Suddenly it was so silent, you could have heard a single hailstone fall.

‘Her snow cannot settle. The skies are so warm that glaciers are melting and falling into the sea. Daffodils that shouldn’t appear till spring pop up in December. Seasons are merging and breaking apart, confusing wildlife.’

‘We must do something!’ Casper cried, loud and clear, piercing the concerned clamour.

‘We are going to do something,’ Bianca said, grateful for Casper’s support. ‘We are going to SAVE IT!’

Out of the corner of her eye, she saw an angry-looking Jack yank Pitter and Patter off the stage.

‘Each of you is here because you are special.’ Bianca turned her head, taking in every child. ‘You love winter. You have been chosen to be one of the Snow Queen’s Ice Children.’

‘Ice Children! Ice Children! Ice Children!’ Casper started chanting, and the crowd joined in.

Bianca glanced nervously at the side of the stage. Jack was standing with arms crossed, staring at her.

‘Each of you will tell your friends, your brothers and sisters, your cousins, of the things we must do to save winter. We will create a world of Ice Children who will do all they can to make this planet a place where winter is respected, celebrated even. We may be young, but there are many millions of us on this planet. We are the future, and we can make a difference.’ She tipped back her head and shouted with her whole heart. ‘WE WILL MAKE A DIFFERENCE!’

‘YES!’ shouted the Ice Children.

‘I will. I promise to protect it,’ came the cacophony of calls. ‘Me too. I love winter!’

‘Inside the heart of every Ice Child lives your winter spirit animal, reminding you of what we’re fighting for.’ Bianca put her arm around Pordis. ‘Together, we WILL save winter.’ She punched her fist into the air.

The mood of the crowd had changed. It was focused and urgent, quick to listen and respond to her cues.

‘It is a tradition of nature that winter is heralded by a very special someone.’ She opened out her arms. ‘Please give a wonderfully cold welcome to the one and only . . . Jack Frost!’ Bianca pointed to Jack as she retreated to the opposite side of the stage, leaving the platform for the figure of Frost. Her heart felt as if it were beating inside her skull. Would it work? Would Jack follow her lead and see that there was another way?

‘My friends, children and creatures of winter . . .’ Jack’s eyes searched the passionate faces of the crowd, then turned a piercing gaze on Bianca.

She held her breath.

Suddenly Jack’s hand flew forward, shooting streamers of ice over the heads of the audience. ‘She gave the Earth the gift of a crystal flake –’ Frost’s crackling voice rose like a ringmaster’s – ‘wrapping her arms around the planet so life might be created. She cleansed the atmosphere of methane, wiped out the dinosaurs and turned this spinning sapphire globe into a giant snowball!’ Jack’s hands moved as if conducting an invisible orchestra. A towering tsunami of snow rose up behind the backdrop and everyone looked up. Jack’s voice grew louder. ‘She is a birther of gods, a beginner and ender of life. She is Old Hiam, the Winter King, but you like to imagine her in a dress. Please give it up for Ishild, my big sister and your SNOW QUEEN!’

The children were silent, their mouths open, looking up in awe, too stupefied to be scared. The giant wave of snow looked as if it were about to sweep them all into oblivion . . . when it froze, solidifying, as if time had stopped. A sparkling sleigh crested the wave, and a gentle flurry of flakes accompanied the descent of Ishild. The sleigh swooped down the wave, pulled by the unicorn.

The children erupted, jumping onto their seats and waving. Bianca’s heart swelled as she spotted Finn sitting between Ishild and Sposh, waving too. The sleigh slid to a halt in the middle of the stage. The unicorn whinnied, its glistening horn scattering rainbows of coloured light, and the audience sighed.

Jack offered a hand to Ishild, bowing as she stepped lightly from the sleigh, clutching Finn’s hand. Sposh tumbled out of the sleigh after them.

Jack dropped to one knee. Quilo, Pitter and Patter moved to the back of the stage and did the same. Bianca copied them, and the audience of Ice Children followed.

A jingle of sleigh bells indicated they could rise, and Bianca gasped to see that the Snow Queen had let go of Finn’s hand.

Ishild was hovering in the air above the stage, looking as if she’d been carved from snow by an artist. Over her gown of fine snowflake lace, she wore a short jacket made of frost froth, and her hair stood impossibly high: pointy blue stalagmites encircled by a diamond crown. Her symmetrical features were of fairy tale proportions and her big eyes were devoid of pupils, like Jack’s. Bianca thought she looked like a beautiful doll.

‘My children.’ Her voice, as soft as falling snow, settled in their minds. ‘This girl speaks the truth. If you cannot keep this world temperate enough for me, then I will have to leave it.’ She turned her head, bestowing a benevolent smile on all her Ice Children. ‘Tonight is the winter solstice, the longest night, when I am at my strongest, and yet, still, I am melting.’

She gestured to the dripping hem of her skirt, and a concerned murmur could be heard from the children in the theatre.

‘We will help you,’ Gwen called out, looking distraught. ‘Please don’t melt.’

‘It will take more than the few of you here to make a difference,’ the Snow Queen said inside their heads, not needing to raise her voice above the alarmed clamour that was growing in the theatre as her icicle hair wilted. ‘It will take every child in the world to restore harmony. But it can be done. One snowflake will melt on its own, but billions of them together –’ her graceful arm lifted, gesturing to the frozen tsunami behind her – ‘are powerful enough to change the face of a planet.’

‘We will save you!’ Casper cried out. ‘I will dedicate my life to it.’

‘And me!’ said the boy standing beside him.

‘I promise,’ came a blizzard of voices. ‘I swear!’

Bianca came forward, held her hand over her heart, and shouted, ‘I, Bianca Albedo, promise I will dedicate my life to saving winter, and will for evermore be one of the Ice Children.’

Other hands covered hearts. She saw Sophie Lilley and Gwen repeat the promise. The whole amphitheatre was reverberating with the words. Bianca turned to see Jack’s frosty face shining with wonder and hope.

In the silence that followed, Ishild opened her arms, inviting the children to approach. Finn tried to take her hand, but she shook her head. Bianca could see how much it distressed her brother to see the Snow Queen melting.

Finn’s mouth turned down, his eyes filled with tears and then suddenly he vanished, leaving behind a handful of snowflakes dancing in the air like tiny white ballgowns whirling to inaudible music.

Bianca gasped. She had hoped, but not dared believe, that this might happen. The love Finn had for Ishild had warmed his frozen heart. The distress he felt at seeing her melt had made him cry. That was how Jack had forced the mirror shard out of Bianca’s heart, and now it was out of Finn’s.

She saw Jack go to the spot where Finn had vanished. He bent down, picked up something tiny from the stage and pocketed it.

One after another, the children came to meet their beloved Snow Queen. They wept to see how she struggled to keep her form, and they too vanished, leaving behind only puffs of flakes.