The slide had delivered Bianca into a cavernous hall. The ice walls were intricately carved into a forest mural depicting skeletal trees devoid of leaves.

‘You won’t be able to take Finn with you when you go,’ Jack said matter-of-factly as a breathless Bianca struggled dizzily to her feet. ‘He is the Snow Queen’s favoured one. But you will get to say goodbye.’

‘I’m not going anywhere without Finn,’ Bianca replied obstinately. ‘He was my brother first and he’s my favourite one.’

‘We’ll see.’ A whisper of a smile played across Jack’s lips. ‘I suspect you won’t be able to stop yourself.’

Jack’s confidence made Bianca nervous. She felt as if she were walking into a trap and resolved to be on her guard.

Marching towards a pair of grand doors, boots clicking on the polished floor, Jack threw up a snowflake hand, snapping icicle fingers. The doors flew open.

‘Jack!’ cried a joyful voice that struck Bianca’s heart like a hammer blow.

Running past Jack, she burst into a room with a dais at one end. On it sat an elegant throne that appeared to be carved from bone and studded with diamonds. In front of the throne, sitting on the floor, was an extraordinarily beautiful girl. Her hair stood up in pointy blue icicles and was crowned with a twinkling tiara. Her dress looked to be made of the finest lace. She was holding hands with a blond boy in navy starred pyjamas, and they were laughing as a snow hare leaped around performing somersaults in front of them.

‘Finn!’ Bianca cried out. She was about to run to her brother when Jack held out an arm to stop her.

‘Her Majesty, Queen Ishild, bringer of snow.’ Bowing low to the girl on the floor, Jack shot a blank look at Bianca, indicating with a tiny nod that she was to do the same.

Bianca dropped into an awkward curtsy.

‘Rise,’ a soft voice said inside Bianca’s head.

But Bianca stumbled forward, falling to her knees before her brother. ‘Oh, Finn, I’ve found you at last! Are you all right?’

‘Hello.’ Finn had a distant look in his blue eyes. ‘I’m all right, thank you. How are you?’

‘Finn, it’s me.’ Bianca searched his face for signs of recognition.

‘Who are you?’

‘Bianca, your big sister.’ Her heart sank. ‘Don’t you remember?’

‘She’s funny.’ Finn flashed his toothless smile at the beautiful girl holding his hand, and Bianca felt a stab of jealousy. ‘Ishild is my big sister.’

Ishild smiled and nodded.

‘No!’ Bianca said, hurt by the affection she saw in his eyes. ‘I’m your sister!’

‘I have two sisters,’ Finn said, ‘but none of them are you. Ishild makes it snow with her thoughts and Patter dances sleet from her feet.’ He studied Bianca. ‘What can you do?’

‘Er . . . nothing,’ Bianca admitted, feeling a bubble of grief ballooning inside her chest. ‘Finn.’ She leaned towards him and noticed Jack step forward protectively. That nervousness gave her hope. Perhaps there was something that she could do that would reach Finn. ‘I am Bianca. But you call me Yanka, because when you were little, you couldn’t say the B. I . . . We . . .’ A memory of the two of them bouncing on a big bed came into her mind. ‘At home, we play Bonky Smash together . . .’

Her throat tightened at the thought of home. A powerfully strong memory of the place suddenly blossomed in her mind. She almost gasped at the recollection. She pushed the memory away, searching her brother’s eyes for any sign that he remembered. She wrung her hands and felt the little red scarf round her wrist. Pulling it free, she suddenly knew what it was. ‘Look, Finn, this is Sposh’s scarf. Your toy rabbit. You remember Sposh, don’t you?’ She held it out. ‘You take him everywhere.’

A flash of recognition shifted the faraway look in Finn’s eyes as he took the red scarf. He stared at Bianca.

‘Sposh isn’t a rabbit,’ Jack said as Ishild pulled Finn back towards her, tightening her grip on his hand. ‘He’s a snow hare, and he’s not a toy.’

The snow hare who’d been performing tricks when Bianca had entered the room hopped between her and Finn.

‘Yes,’ agreed Finn, his eyes misting over as he tied the scarf round the hare’s neck. ‘Here you are, Sposh. The girl has brought you a lovely red scarf to wear.’

The hare bounced about, delighted. Bianca realized with a sinking feeling that this was Finn’s winter creature. What need had he for a toy?

‘What have you done to him?’ Bianca turned on Jack, getting to her feet, her fists clenched. She shouted, ‘Why doesn’t he know who I am?’

The hare’s ears drooped as the little creature began to shiver.

‘Hey!’ Finn said, gathering the white snow hare in a cuddle with his free hand. ‘Don’t you shout at my brother. You’re frightening Sposh.’ He stroked the hare’s long white ears. ‘I think you’re mean. I don’t want you to be my sister! Go away!’

‘Jack isn’t your brother!’ Bianca exclaimed, feeling the bubble of emotion in her chest growing. ‘Ishild is not your big sister, Finn. I am!’

’You’re a liar.’ Finn shook his head, clutching Ishild’s hand tightly, and Jack smiled.

Before she knew what she was doing, Bianca had lurched between them and yanked Finn’s hand free from Ishild’s. ‘She is not your sister!’

Ishild made a strange gurgling sound and slumped backwards. Bianca saw with horror that her perfectly symmetrical features were sliding down her face. Her hair and the lacy hem of her dress were dripping. The girl was melting.

‘GO AWAY!’ Finn shouted at Bianca, grabbing Ishild’s hand and hugging it. ‘I HATE YOU!’

As Finn held the young Snow Queen’s hand, the dripping came to a stop. Ishild lifted her head, and her eyes settled back into their original position. She sat up, smiling tenderly at Finn.

Bianca was awash with panic. Everything she was doing was making the situation worse. This was not how she’d imagined finding Finn. She turned and looked directly into Jack’s blank eyes.

‘Please don’t do this,’ she begged. ‘I love my brother. I’ll do anything. Please.’ She had come so far searching for him. Her only thought had been to rescue him and bring him home. She’d assumed that’s what he would want too. She’d imagined him being happy to see her, throwing his arms around her so she could whirl him about like they did when they played at home. Home! The memory came again, even stronger than before. She remembered her bedroom and her books. The bubble of sadness and grief grew in her chest until it seemed to push everything else aside. She missed home.

Another memory hit her like a snowplough. An image of her mum and dad asleep on a park bench, leaning against one another, in front of a frozen Finn. She had forgotten them! She had forgotten her parents! The picture was so powerful that she felt her heart shudder. She bent double as it stole her breath. How could she have forgotten them? Her mum had knitted the purple jumper she was wearing. She felt the weight of her left hand and knew her father was holding it.

‘Oh!’ She gasped as tears flooded into her eyes.

I know my heart can’t be turning to ice, she thought, because it’s hurting.

‘I knew you wouldn’t be able to stop yourself,’ came Jack’s gleeful voice.

Tears cascaded from Bianca’s eyes and down her cheeks as her body grew heavier and heavier. She collapsed to the floor, looking up at Finn through a blur of tears.

Clutching Finn’s hand, the Snow Queen gave Bianca a look of curious pity and leaned towards her. Inside her head Bianca heard the whispered words:

‘I am old and new.

I am truth and lies.

I’m made from everything and nothing.

I have the power to change the world.

What am I?’

Darkness descended and in her mind she heard Pordis cry out, ‘Bianca!’