I heard a scraping noise from the staircase and, thinking that maybe tea had arrived, I stuck my head around the corner to see if I could help. To my amazement, Hugh Oswald was making his way up the stairs to see me – one step at a time. When he saw me he raised a shaking hand in greeting, but was obviously too breathless to speak. I moved to help him, but he waved me away, shaking his head. It took him at least ten minutes to reach the study, and at the end he accepted my arm over to a hastily cleared spot on the sofa.

He sat down gratefully and wheezed at me while making apologetic little gestures. It was painful to watch. I offered him a drink from the bottle of water I had in my bag and he took it gratefully, making sips between gasps.

‘I don’t think you should have come up those stairs,’ I said.

The wheezing became suddenly ragged, which worried me until I realised he was laughing.

‘I had a chance at a bungalow in the Palladian style,’ he said. ‘But I wanted the tower.’ He paused for breath again. ‘You can’t even fit a chairlift, either – Mellissa spent almost a year trying to find a way. Perils of living in a listed building.’

I offered to go fetch Mellissa, but he was having none of that.

‘She’ll come looking for me soon enough,’ he said. ‘I wanted a bit of time alone with you. And she does fuss.’

‘If you’re sure,’ I said.

His face lost some of its livid mottling and his breathing its rasping edge.

‘I’ve got something for you,’ he said and directed me over to a chest that had been hidden under a dusty red floral cushion and two volumes of the Encyclopaedia Britannica. I opened it up and smelt camphor and the warm smell of old cloth. Inside was a long cylindrical khaki bag with a rough webbing shoulder strap. I’ve spent enough time rooting around in the Folly’s basement to know army surplus when I see it. Stencilled along the side of the bag was Oswald, H. 262041 and it was held closed with three buckles. The contents were heavy – at least two or three kilos, I reckoned, when I lifted it out of the chest. Under Hugh’s direction I placed it on the floor in front of his feet and crouched down to unbuckle it.