Because I wanted to keep the perfume simple I added carrot seed oil for its smell of damp dug-over earth, ambrette for a hint of spicy sweetness and frankincense because I had a large unopened bottle handy and I thought it would add a nice incense-like smokiness to the drydown. The component that eluded me was petrichor, the mineral, flinty smell associated with rain falling on warm, bone-dry earth.

The perfume oil I made wasn’t a bad scent – in fact it was nice – but I was disappointed that it had failed to capture my intention. It would never cause the wearer to breathe deeply and smile with pleasure or wonder. I needed something to lift it out of the ordinary, but nothing I tried worked. For some reason it remained a tad murky, like a pot of soup reheated once too often.

It was then that I thought of my grandmother’s uranium bottle. I found it in my jewellery box and placed it on the table next to the boronia blend. I hadn’t looked closely at the bottle since Lange’s speech and I’d forgotten how lovely it was. The strange yellow-green glass was faceted, designed to resemble the surface of a scallop, though its overall shape was more like a flattened pine cone. It was more beautiful than I remembered and I spent a few minutes holding it up to the sun, tilting it this way and that to capture the light. Where the sun hit the bottle the glass was pale yellow, but where it was thickest it was the colour of unripe lemons. It was the only thing I owned from my grandmother and I’d kept it with me whenever I’d moved flats or cities. The brown gunk was still in the bottom of the bowl and I enjoyed it for one last time before carefully transferring the juice of Thora’s perfume blend from its plain, dark-brown, screw-capped bottle to the rare green bottle in my hand.

I carefully carried Thora’s perfume around in my pocket for two weeks before I saw her again. I grew used to the feel of its cool ribbed glass against my fingers every time I reached for my hanky or change. The perfume had started to develop in the short time since I’d created it. The individual oils were becoming less harsh and more rounded as they settled into one another. The ambrette, which had threatened to overpower the boronia, had slipped into the background, and the boronia itself was becoming more jam-like, its berry richness edging towards damask rose.