The snow had forced them to stop on the mountain path for what seemed like the hundredth time. Ada grizzled in the crook of her arm, but Rosa couldn’t comfort her. Her bones had turned to lead. Her heart was a stone. It could not be possible that she was returning home with only one baby rather than two. It simply could not be possible. And yet the fact was that she would never hold her daughter again, never see or smell her. Esme was truly gone. Rubbed out like she’d never existed. A small footnote in the book of their lives.

The door opened and a blast of cold air blew into the stuffy interior, along with a flurry of snow, as Eustace climbed up. The small carriage rocked beneath his weight and Rosa caught a glimpse of the swirling ice crystals and glittering frost in the frozen world beyond, before the door slammed shut.

‘We’ve dug out the carriages,’ he said, each word smoking before him in the dimness. ‘Are you sure you don’t wish to get out and move around a little before we start off? It might help to warm you.’

Rosa shook her head. She’d removed her travel gloves in order to hold Ada closer, and the blood opal gleamed like an eye in the darkness. The brushed-velvet curtains stiffened in their coats of ice at the windows. The cold bit deep into her bones like teeth of broken glass, but she was barely aware of the discomfort. Esme was cold, so she would be too. Coldness was nothing.

Eustace sighed and rapped on the roof of the carriage. Rosa heard the driver speak to the horse and then there was a jerk as the brougham started forward, rattling them around inside like popcorn in a popper.

If only Esme had been one of her clockwork creatures, then Rosa could have opened her up and fixed her. How many times had she brought some clockwork rabbit back to life after all the other artificers had given up? But there were no cogs and wheels inside Esme, and a stopped heart wasn’t a stopped clock. No one and nothing in the world could fix this. No key could wind back what had happened.

‘How long until we reach Turin?’ Rosa asked in a small, hoarse voice that didn’t sound like her own.

‘The driver thinks another five hours,’ Eustace said.

That would make eleven hours altogether. Eleven hours of jolting around in this carriage with the man she despised most in the world.

I cannot bear it, Rosa thought. I will go mad before we get there.