Tyburn gave me a sharp look and started arranging the roses. The vase was unremarkable, fat-bottomed like a volumetric flask and made from green lacquered fibreglass, the sort of thing you can pick up for fifty pence at a car boot sale. ‘I’ve got nothing against the Old Man or his people, but this is the twenty-first century and this is my town, and I haven’t busted a gut for thirty years so that some “gentleman of the road” can move back in and take what’s mine.’

‘What do you think is yours?’ I asked.

She ignored me and, having arranged the last of the roses, placed the vase on the patio wall close by. When I’d bought them the roses had been the last of the stock and were beginning to wilt on the stand. Once Tyburn placed them in the vase they perked up, becoming full, rich and even darker.

‘Peter,’ she said, ‘you’ve seen the way the Folly is organised, or rather not organised. You know that it has no official standing in Government, and its relationship with the Metropolitan Police is entirely a matter of custom and practice and, God help me, tradition. It’s all held together with spit and sealing wax and the old boy network. It’s a typical British mash-up, and the one time it was asked to step up it failed horribly. I have access to files you don’t even know exist, Peter, about a place in Germany called Ettersburg – you might want to ask your mentor about that.’

‘Technically he’s my Master,’ I said. ‘I swore a guild oath as his apprentice.’ My tongue felt thick and dry, as if I’d just spent the night sleeping with my mouth open.

‘I rest my case,’ she said. ‘I know it’s against the national character but don’t you just wish we were a little bit more organised about these things, just a tad more grown-up? Would it kill us to have an official branch of government that handled the supernatural?’

‘A Ministry of Magic?’ I asked.

‘Ha-bloody-ha,’ said Tyburn.

I wanted to know why she hadn’t offered me a cup of tea. I’d brought her flowers, and figured the least I could expect in return would be a nice cup of tea or a beer, or even a drink of water. I cleared my throat and it came out a bit wheezy. I glanced at the fountain and the water streaming into the basin.

‘Do you like it?’ she asked. ‘The basin is a rather crude seventeenth-century knock-off of an Italian design, but the central figure was excavated when they were building Swiss Cottage station.’ She rested her hand on the statue’s face. ‘The marble’s from Belgium, but the archaeologists assure me that it was carved locally.’