He looked me right in the eyes when he said this, as though daring me to discuss it with anything other than a doctor’s clinical detachment.

The waiter returned. In a few moments Ian was working chablis around his mouth, energetically, as though it were Listerine. I was thinking of how the waiter, his Adam’s apple prominent and bouncing, had described the wine; I remembered the phrase lingering finish.

‘Will you keep it?’ I said.

‘Pardon me?’

‘The stone. Or stones.’

Ian looked at me sharply.

‘I hadn’t planned to,’ he said. ‘No.’

Some smoke arrived under tiny bell jars. The waiter’s hands shook as he set them down. The glass jittered. The dish was called Memory of Lamb.

‘I read something about people who keep their kidney stones,’ I said.

‘I don’t think I’ll want a souvenir.’

‘Didn’t Benjamin Franklin keep his?’

Ian twisted in his seat, plainly uncomfortable. ‘Even so,’ he said.

I paused to lift the bell jar. I wasn’t sure whether this dish was supposed to make me remember lambs I’d eaten, or whether I was inhaling the memories of an actual lamb.

‘They’re quite beautiful,’ I said. ‘Kidney stones. Up close, I mean.’

It was a half-truth that I’d read about people keeping their kidney stones. I’d actually watched a documentary about kidneys during one of my long summer afternoons on the couch waiting for a shift at the call centre. The documentary, part of a series on the human body, showed magnified images of stones people had passed. They were made up of layer upon layer of mineral deposits. They looked like geodes, or something chipped off a coral reef. They glittered when they caught the light.

‘People make jewellery out of them,’ I told Ian.

‘People do all sorts of strange things,’ he said.

At the bottom of The Gander’s menu, there was a note: We cook from the heart. Cooking from the heart, I came to learn, involved a sous-vide machine, and micro herbs applied with tweezers. It involved tongue, basil ice cream, and balsamic in fat, amoeba-ish drops on the plate.

Between one course and another I tried to make conversation. I asked Ian how he had come to be interested in mystery dining.

‘Well, I was frequenting restaurants all the time,’ he said, pushing his pinky finger into a seared scallop and frowning. ‘Mrs Morton wasn’t much of a cook. She didn’t care for any of the domestic arts, really. Couldn’t sew a button on. Couldn’t boil an egg. I don’t think she could have told you what colour our vacuum cleaner was.’

I twisted some linguini around my fork.

‘You remember, don’t you? She was always buying profiteroles for Jo’s birthday parties because she couldn’t sling a sponge cake together.’

‘I liked those profiteroles.’

‘You must have been a very sophisticated child.’