Everyone went absolutely silent – all except for the yeti cake, which was still happily performing its song and dance routine.

‘If that’s a joke,’ Felix said slowly, ‘then I must say it’s in very poor taste.’

‘It’s no joke,’ President Fogg said in a clipped voice. Stella saw that he was sweating, and he tugged at his collar as if it were too tight. ‘Look. Could you take off that ridiculous hat? I can’t have a serious conversation with you when you’re wearing it.’

Felix slid the hat off and Stella did the same. The last thing she wanted was to be arrested while wearing a party hat.

‘What are the charges?’ Felix asked.

‘She’s an ice princess,’ the president said.

‘That in itself is not a crime,’ Felix said through gritted teeth. ‘We do not put people on trial simply for being born a certain way.’

Stella’s eyes went to the police officers and she couldn’t help noticing that one of them had a bear-prod hanging from his hip. These were sometimes used as protection to ward off wild polar bears, but Stella didn’t like the way the man’s hand twitched towards it as he stared at her. These weapons delivered a shock big enough to take down a 400-kilogram bear. Surely he wasn’t planning to use it on her?

‘She’s also been accused of theft,’ President Fogg went on. ‘At the celebration dinner upon your return from that joint expedition, there was a dancing penguin named Monty—’

I took Monty from the club,’ Felix said. ‘You were going to have him stuffed otherwise. It was me. I take full ownership. You can’t have him back either, by the way. He’s nesting in our parlour.’

‘It doesn’t matter,’ President Fogg said brusquely. ‘Someone has made an application to the Court of Magical Justice in the Black Spells Forest to have certain … restrictions placed on the girl’s movements, on account of her being a danger to society.’

The others all began to protest, and Stella felt frustrated tears fill her eyes. Her throat ached with the effort of not giving in to them.

‘That’s a lie!’ Beanie cried, blinking rapidly. ‘It isn’t right to tell lies! Stella isn’t a danger to society!’

‘Well, that is what the Court of Magical Justice will look into—’

‘The prejudice and bigotry of Wendell Winterton Smythe, and others like him, is far more of a threat to society than Stella will ever be!’ Felix exclaimed.

‘That’s for the court to decide,’ President Fogg said. He looked at Felix. ‘Be reasonable, Pearl,’ he said in an imploring tone. One finger twirled his moustache in a restless manner. ‘When you took the girl from the snow, you didn’t know what she was – everyone realises that. But one can’t have ice princesses simply running about loose in civilised society— Oh, for goodness sake, could whoever’s birthday it is, please blow out that yeti’s candle?’ he snapped. ‘The wretched thing won’t stop singing and dancing until you do.’

‘Don’t forget to make a wish!’ called out a passing waiter cheerfully. He was clearly quite oblivious to the context of the moment, because he deftly popped paper party hats on President Fogg and the two constables as he walked by.

Beanie glanced at Stella before looking back at the dancing yeti. He muttered his wish quietly beneath his breath, but Stella saw his lips moving and understood what he’d said.

‘I wish for a diversion.’

The moment Beanie blew out the candle the yeti went silent and still, becoming just an ordinary piece of birthday cake …

One of the constables gave a shocked-sounding yelp. Stella thought he was perhaps just impressed with the yeti cake at first, but then she looked at him and saw there was a bug-eyed, web-footed snow goblin, determinedly wriggling out from beneath the paper hat. The constable tore it off, and several more snow goblins tumbled out, clinging to the constable’s sleeves and collar. They looked momentarily stunned, blinking in the bright light, before they did what snow goblins do best and sank their teeth into the man’s skin. The goblins had needle-sharp teeth, so it was no surprise that the constable let out a howl and lurched back into a nearby table, sending an entire sugar castle crashing to the floor. The goblins tumbled onto the table and immediately snatched up toothpicks, which they brandished like swords. The family who’d been eating there quickly pushed back their chairs with shrieks of alarm.

‘Oh, sorry! Sorry!’ The waiter hurried about, flapping his hands in agitation. ‘I didn’t realise those were snow-goblin hats.’

‘Good gods, man, why would you have snow-goblin hats to begin with?’ the president cried. He tore off his own hat, and a dozen snow goblins fell down the front of his coat with little giggling sounds.

‘They’re for troll parties!’ the waiter groaned. ‘Their little nips are extremely ticklish to troll children, you see, and—’

‘Aarghh!’ The second police officer let out a scream as he tore off his own hat to reveal a particularly wild-looking snow goblin biting his head. ‘Little nips? This one’s actually biting my head off!’

At the same time, one of the other goblins leapt from the table and started jabbing at ankles with its toothpick. As the waiter flapped around, trying to deal with three panic-stricken men at once, Stella and the others hurriedly got to their feet. Felix threw some money down on the table and then they were slipping away, racing out through the door and into the street. It had gone dark while they’d been having dinner and snow was falling again, drifting past them in the light from the lamp posts. It was ferocious, biting, savage snow – the type that might have goblins in it – and it seemed to have driven most people indoors, for there was hardly a soul around. It muffled all the noise too, and everything seemed still and quiet, as if they had suddenly found themselves trapped inside a snow globe.

‘They’ll be right behind us,’ Felix gasped. ‘We’re going to have to leave now. Tonight.’

‘But how?’ Joss said, looking around. ‘We won’t be able to get a train at this time. And we can’t outrun them either.’

They heard the sound of raised voices from the restaurant behind them and Stella knew that President Fogg and the police officers would come bursting out of those doors at any moment. She couldn’t go to prison. Not now when she needed to find the Book of Frost to save Shay. Without her, the whole plan fell apart.

She glanced down at the charm bracelet around her wrist. There were fourteen silver charms on it altogether, all related to some kind of magical spell. Jezzybella couldn’t remember what most of them did, and she and Felix thought it was too dangerous for her to try them out. But her old nanny did remember a couple of them, and now Stella’s attention fixed on one charm in particular.

‘I know what to do,’ she said.

Nestled beside a yeti charm and a fairy charm was a tiny silver carriage. Stella had practised doing this particular spell in the garden back home with Jezzybella, but had never managed to make it work.

‘You don’t want it enough,’ the old witch had said. ‘That’s why it ain’t working. You’ve got to want it more than anything else in the world.’

At the time, what Stella had wanted most had been to go for a gallop on her unicorn, Magic. Right now, though, she wanted that carriage as much as she wanted to breathe. Her desperation and panic made her heart pound hard inside her chest and adrenaline surged all the way through her as she placed her bare fingers to the carriage charm, cold as ice to the touch, closed her eyes, and concentrated with everything she’d got.

There was a soft, silver pop right in the pit of Stella’s stomach, and then the swish of a blade. Stella heard the gasps of the others. She opened her eyes to see a massive polar bear standing directly in front of her, tipping back her head and roaring into the night sky, shattering the snow-silence into little broken pieces.

The others all shrank back, but Stella wasn’t afraid of the polar bear. In fact, there were two of them, and they were tethered to a magnificent ice sleigh. It shone silver and white in the moonlight, with a great curved back hung with deadly-​looking icicles, and an elaborate front engraved with snowflakes and crowns and yetis. A troll carved from ice crouched there, hunkered down against the cold, clinging to the front of the sleigh with one hand and holding out a lantern with the other. Its large, bat-like ears sparkled in the bright white light cast by the lantern. In fact, the entire ice sleigh glittered in the night like diamonds.

The second polar bear pulled her black lips over her gleaming white teeth and snarled into the snow, and Stella realised that these bears were not like Gruff, her beloved pet back home. They hadn’t been brought up in captivity, and they had no interest in cuddles and fish biscuits. These were snow queen bears, savage and wild and untamed. Yet Stella felt no fear as she walked towards them. One of her companions  – probably Beanie  – gave a frightened squeak, and the jungle fairies promptly started up their chant of doom, but nobody tried to stop her from approaching them.

Like Gruff, these bears were gigantic, and even standing on all fours they looked Stella straight in the eye. She could hear them both growling slightly in the back of their throats, lips pulled back in an uncertain snarl, thin lines of drool stretching between their teeth. Slowly, Stella held out her hands, offering her palms to the bears.

Up close, she could see that there was snow encrusted on their coats, around their paws and on their backs, as if they’d come straight through a blizzard to get here. She noticed that their huge paws had made bear-prints in the snow, their breath smoked in the freezing air and steam rose from their wet coats. They were real flesh-and-blood creatures – not shadow animals like Koa.

Silver harnesses clinked around their massive shoulders, and both bears continued to growl while sniffing at Stella’s skin and peering at her. She thought she should probably be more frightened  – after all, either one of these animals could kill her instantly with just a single bat of a great paw – and yet she knew, somehow, that they wouldn’t harm her.

After a couple of breathless moments, the quiet, rumbling growl ceased. Stella could still see plenty of dangerous wildness gleaming in their dark brown eyes, but some small shift seemed to take place so they were suddenly calmer and quieter, and she could see wisdom in their gaze now. She knew she’d never be able to cuddle these bears, but she thought they were just wonderful even so, and the sight of them snorting their frozen breath in the lamplight filled her with a deep sense of pleasure. Best of all, there was no chilling sensation around her heart, as there had been when she used ice magic. She still felt completely and truly herself, which wasn’t something she took for granted any more.

‘Everyone,’ Stella said, speaking quietly so as not to alarm the bears. ‘Get onto the sleigh.’

There was a moment of hesitation, but then Felix stepped tentatively forwards and the others followed him.

‘Amazing!’ Shay breathed, resting one gloved hand on the edge of the sleigh. He glanced at Stella and gave her a wide grin. ‘You’re amazing, Sparky,’ he said.

Stella gave him a pleased, slightly embarrassed smile back. It always gave her a small flutter of delight when someone reacted positively to her frost magic rather than negatively, and it was good to hear Shay’s old nickname for her again.

But then the door burst open behind them and President Fogg came rushing out, with the two police officers right on his heels. One of them had the bear-prod in his hand, although it dangled loosely from his grip, like he wasn’t quite sure what to do with it. The other officer had a furious expression and a toothpick sticking out of his neck – a parting gift from some snow goblin.

‘Quick!’ Stella gasped, urging everyone to climb into the sleigh.

They tumbled in to land on the silky soft reindeer skins piled up on the seats. The sleigh was so big there was easily room for all of them.

‘Don’t just stand there!’ President Fogg roared. ‘They’re going to get away! Stop them!’

Standing in the snow by the bears, Stella glanced over her shoulder to see the officer with the bear-prod step forwards with a great air of reluctance. She guessed he had never confronted a real live bear before, let alone an ice princess. He had the look of a man whose day was not going at all to plan, and Stella saw that his face and neck were covered in goblin bites. She felt a momentary flash of sympathy for him, but then he brandished the bear-prod at her, and she saw in his eyes that he meant to use it.