For some inexplicable reason the Metropolitan Police don’t have a standard form for ghosts so I had to bodge one together on an Excel spreadsheet. In the old days every police station used to have a collator – an officer whose job it was to maintain boxes of card files full of information on local criminals, old cases, gossip and anything else that might allow the blue-uniformed champions of justice to kick down the right door. Or at least a door in the right neighbourhood. There’s actually a collator’s office preserved at Hendon College, a dusty room lined wall to wall and top to bottom with index-card boxes. Cadets are shown this room and told, in hushed terms, of the far-off days of the last century, when all the information was written down on pieces of paper. These days, provided you have the right access, you log into your AWARE terminal to access CRIS, for crime reports, Crimint+, for criminal intelligence, NCALT, for training programmes, or MERLIN, which deals with crimes against or involving children, and get your information within seconds.

The Folly, being the official repository of the stuff that right-thinking police officers don’t want to talk about and, least of all, have floating around the electronic reporting system for any Tom, Dick or Daily Mail reporter to get hold of, gets its information the old-fashioned way – by word of mouth. Most of it goes to Nightingale, who writes it out, in a very legible hand I might add, on paper which I then file after transferring the basics to a 5x3 card which goes into the appropriate section of the mundane library’s index-card catalogue.

Unlike Nightingale, I type up my reports on my laptop, using my spreadsheet form, print them and then file them in the library. I estimate that the mundane library has over three thousand files, not counting all the ghost-spotting books left uncollated in the 1930s. One day I was going to get it all onto a database – possibly by teaching Molly to type.

Paperwork done, I did half an hour, all I could stand, of Pliny the Elder, whose lasting claim to fame is for writing the first encyclopaedia and sailing a tad too close to Vesuvius on its big day. Then I took Toby for a walk round Russell Square, popped in for a pint in the Marquis and then back to the Folly and bed.