He nods. ‘It’s used all over the world as a sort of gold standard. If you are in a public building, you must be able to get to a place of safety in two and a half minutes. As I said, my sister is a real expert on it and would be able to tell you about the Occupation Capacity of buildings and the importance of Door Exit Widths but I won’t attempt to explain them. There’s a lot of debate about whether it’s still valid as a standard, but I guess if you change it, you have to have evidence for what it should be changed to, and perhaps that’s more trouble than it’s worth when the rule seems to work.’ He laughs. ‘You can imagine Christmas dinner at my folks’ house, though. My mum and I just go out into the kitchen and sort out the roast potatoes and leave them all to it.’

‘We will be getting new smoke alarms here,’ said Georgia. ‘Stan put the old ones in, but that was years ago and there are new regulations coming soon.’

‘Tell me, did you want to be a firefighter?’ Stan asks.

‘When I was small, yes, of course. But once I had the asthma diagnosis, I just stopped thinking about it. There was no point. It wasn’t something I could train for. It doesn’t matter if you can pass all the physical tests if your asthma isn’t stable. I was a bit jealous of my sister I suppose, but I could spend a lifetime cursing nature, and what would be the point? I have a good life and I have the girls, and I was loved very much by a marvellous woman. You can’t regret what’s not possible in the first place.’

Georgia sits back in her chair. ‘When I was a child, we had to do a project in school about the fire at that theatre. I was at South Morningside Primary, actually, where your girls go. I don’t suppose the place has changed much. And Annie, my aunt, told me all about it – she was there, in fact, on the night of the fire, seeing The Great Lafayette. He was a friend of Harry Houdini, and Houdini had given him a dog which died while he was in Edinburgh. He was heartbroken. He somehow persuaded the owners of one of the cemeteries to let him bury the dog there.’

‘A dog? In a cemetery for humans?’ Tess is incredulous.