Rosa would never have seen the boy if it hadn’t been for the fireworks. They shed so much light upon the ground that she glimpsed him disappearing into the dark walk at the edge of the garden. She could even see his withered arm because, inexplicably, he wore no coat. Her heart beat suddenly faster in her chest as the crowd oohed and aahed their admiration at the fiery display overhead. This was the first time she had seen the boy in months – the child whom everyone said did not exist. She glanced at the people around her, but they were all too interested in the sky to notice her, and Eustace had already returned to the house in a sulk.

Rosa was determined not to miss this chance and the snow crunched beneath her boots as she climbed down from the sleigh and hurried after the boy. She had not seen any guests venture into the dark walk – there was too much to capture their attention elsewhere. The snow muffled sound from the garden, and the fireworks filtered strangely through the branches, pulsing in red and orange and silver that made the trees stand out like the silhouettes in the pop-up book.

She hastened along the winding path, afraid she might already have lost the boy, but when she stumbled out into the glade where the carousel had first appeared, she found him. He sat alone on a tree stump, hunched over his knees, with his arms tucked in close to his body, as if he was trying to make himself disappear. Rosa strode towards him, determined to get to the bottom of who he was, once and for all.

‘What on earth are you doing out here?’ she demanded. ‘You’ll catch your death!’

The boy looked up as another firework blossomed in the air overheard, turning the snow pink. Rosa didn’t think she’d ever seen a child with such joyless eyes and the sight made her shiver.

‘Your mother would be furious if she knew you were outside on a night like this without a coat,’ she said.

‘No, she wouldn’t,’ the boy said. ‘She doesn’t want me.’

Rosa was shocked. ‘I’m sure that isn’t true,’ she said. ‘Why would you think such a thing?’

‘She told me.’

There was something odd about him when he spoke, but Rosa couldn’t place what it was.

‘Well.’ She searched her mind for words of comfort. ‘We all say things we don’t mean sometimes. A moment of stress or—’

‘She tells me every day.’ The boy shrugged. ‘But I knew before she told me.’

All of a sudden, Rosa realised what was odd about his speech. Whenever she spoke, her words misted before her in the freezing air, but the boy’s didn’t. It was blisteringly, savagely cold, yet he did not shiver. And the only footprints in the snow were Rosa’s.

There are no children at Raven Hall …