Mathieu started at the suggestion. ‘Wait. The lady cannot go near the furnace. Not in those clothes.’

Jane looked at the fire and she looked at her muslin dress and she looked at the sphere resting on the table. ‘Do you have some trousers I might borrow?’

Emerging from the storeroom in borrowed buckskin trousers, belted tightly at the waist to keep them from tumbling off, and a man’s shirt with the sleeves rolled up to leave her hands free, Jane felt terribly exposed. To be certain, the same amount of material covered her form as before, and the buckskin was sterner stuff than her muslin, and yet for all that, Jane could only think about how her legs were in full view. She kept her back straight and her head high as she marched across the room and took her place by her husband.

He opened his mouth, and she silenced him with a glare of determination.

Mathieu seemed to find everything in the room more interesting than her, checking his tools and the end of the long pole very studiously.

Jane clapped her hands. ‘Shall we?’

For the next two hours, they did. Repeatedly, Vincent cast the simple glamour of the cone and Jane traced it with the threads of cold. Though each attempt ended in failure, they felt that they edged closer to success as Jane learned the amount of cold she had to apply to create a response in the crystal.

The heat from the furnace weighed on her oppressively, magnifying the fatigue from the glamour. Each breath seemed harder to draw. Matching her line to Vincent’s glamour, Jane adjusted the thread of cold, trying to make the place where the glamour should fold more apparent.

With a crack, the crystal shattered.

Yelling as one, they all flinched and ducked as pieces of crystal flew through the furnace room. Glass clattered to the ground. Only the roar of the furnace broke what silence remained.

Hoarse with tension, Vincent said, ‘Is everyone all right?’

‘I am fine.’ Mathieu’s voice cracked.

Jane straightened, the intensity of her emotion making her feel ill. ‘I am so sorry.’

‘But are you well?’

‘Quite. Only mortified that I misjudged so.’

‘Jane.’ Vincent tilted her head up. ‘You are bleeding.’

The room spun around her, but from long practice at keeping herself erect while doing glamour, Jane ignored the black specks that swarmed around her vision. ‘Not much, I presume, or you would be in more of a panic.’

A single, very thin scratch, lay below her right eye. She would not let herself think on what might have happened if the shard had been an inch higher. Nor would she let Vincent do so. As he tried to fuss over her, Jane pressed a cloth to the scratch until she was satisfied that the bleeding had ceased. ‘Shall we begin again?’

‘I think we are done for the day.’ Vincent stood, nodding to Mathieu.