The carriage bumped and lurched its way along, and Rosa’s eyes settled for a moment on a large white butterfly hovering right in front of the window. The ghost butterfly emerged from the snow just as Beatrice had described it, with lacy wings and ivory spots.

She gasped and suddenly the air was full of them, falling and fluttering and dancing in the icy mountain air. Rosa pulled down the window with her free hand, ignoring Eustace’s cry of alarm. She was desperate to catch one of the butterflies, but her fingers were so cold that she could barely move them.

It didn’t matter, because an entire kaleidoscope poured straight in through the open window, with every available surface of the brougham covered in delicate, white, frost-tipped wings. They were on the curtains and the upholstered seats, perched upon the luggage rack and fluttering against the glass of the other window.

‘What in heaven’s name are you doing?’ Eustace demanded, raising his voice above Ada’s cries. ‘Do you want us all to die on this road?’

He reached past her to draw the window closed. For a moment Rosa saw a ghost butterfly perched on the brim of his hat, but then it seemed to crumple and melt away until it was merely a clump of snow. When she looked around the rest of the carriage she saw only crusts of ice and lumps of slush. On the other side of the window there was a brief flutter of pale wings, but then a gust of wind blew sprays of ice across her vision and the butterfly was lost back into the blizzard. The shock of the icy draught momentarily hushed Ada, and the sudden quiet was almost more shocking than the crying.

‘For God’s sake, Rosa,’ Eustace muttered. ‘What were you thinking of?’

Rosa tightened her hold on her daughter and wondered what she would have said to Esme, if she could have sent her a message:

You were loved.

You mattered.

You were my world.

I am so desperately sorry.

But even Beatrice had not been able to track down a ghost butterfly and there was no evidence that they’d ever existed at all. She told herself it did not matter. There was still the Winter Garden competition and the prize of one precious wish. All thoughts of using it on Eustace had vanished. There was something more important now.

I wish that my daughter had not died …

CHAPTER TWENTY-ONE

When they arrived back at Raven Hall, Rosa watched the house being dressed for mourning with a strange sense of detachment. The servants glided about, covering the mirrors and stopping the hundreds of clocks guarding the corridors, but it didn’t feel real. The house was dreadfully silent without the discordant echoes of ticks and tocks, and the covered mirrors meant the rooms were even gloomier than usual.