‘Granddad moved down to this room a couple of years ago,’ said Mellissa and showed me the brand new en suite bathroom with an adapted hip bath, lever taps and hand rails. She snorted when I popped back into the bedroom to check under the bed, but her humour evaporated when she realised I really was going to check the broom cupboards and the wood store.

A circular staircase with bare timber treads twisted up to the first floor, leading me to what had obviously been Hugh’s study before he shifted to downstairs. I’d expected oak bookshelves but instead half the circumference of the room was filled with pine shelves mounted on bare metal brackets. I recognised many of the books from the Folly’s own non-magical library, including an incredibly tatty volume of Histoire Insolite et Secrète des Ponts de Paris by Barbey d’Aurevilly. There were too many books to be contained by the shelves and they had spilled out into piles on the gate-leg table that had obviously served as a desk, on the worn stuffed leather sofa, and any spare space on the floor. Many of these looked like local history, beekeeping guides and modern fiction. There were no magic books. In fact, nothing in Latin but the very old hardback editions of Virgil, Tacitus and Pliny. I recognised the Tacitus. It was the same edition Nightingale had given me.

It was all a bit short on missing children, so I had Mellissa show me up the stairs to her bedroom, which took up the whole of the top floor. There was a Victorian vanity and a Habitat bed and wardrobes and chests of drawers that were made from compressed and laminated chipboard. It was quite amazingly messy; every single drawer was open and from every single open drawer hung at least two items of clothing. Just the loose knickers would have caused my mum to do her nut, although she would have had some sympathy for the drifts of shoes piling up at the end of the bed.

‘If I’d known the police were coming,’ said Mellissa, ‘I’d have had a bit of a tidy.’

Even with all the windows open it was warm enough to pop beads of sweat on my back and forehead. There was also a sickly sweet smell, not horrible, not decay, but all-pervading. I saw that there was a ladder built into the wall and a hatch above it. Mellissa saw me looking and smiled.

‘Want to have a poke in the attic?’ she asked.

I was just about to say ‘of course’ when I became aware that the deep thrumming sound that hovered on the edge of audibility throughout the rest of the house was louder here and, predictably, coming from the attic.