But, abandon it she had, and had set up above a shop selling umbrellas, from which vantage point she began to make her living, giving personal appointments to solve problems, or group sessions for reasons which escaped me but seemed to be little more than light entertainment. On rare occasions she made house calls, but preferred to receive her clients in her room, which was decorated in dark colours, with aromatic candles burning all day and night and windows permanently shrouded in heavy curtains. The police investigation revealed why she did not like to perform elsewhere. She would have had to try and convince her customers without the benefit of all the little bits of trickery and stagecraft that were found stacked in the next room. The cupboards with fake doors; the bells with string, so they could tinkle mysteriously, controlled by unseen forces; the source of a mysterious purple light, which looked as though it had been bought from a theatre; the echo chambers so her assistant could make the noises of spiritual beings unseen by the rest.

The woman was a total fraud, in other words, and it was unfortunate that we reporters – who love a good tale of human foolishness – printed all this in cheerful detail before the police managed to interview her clients, as many of them refused to come forward out of simple embarrassment. If she had ever had an appointments book, it had vanished as well, as had the assistant, who, it emerged, had been a prostitute trying to improve herself.

All in all, then, a squalid business, as was her death. For she had been strangled with the velvet tie of the robe she wore when performing. The murderer had acted with force, and thoroughness; making sure of the matter by then crushing her skull with a heavy brass candlestick. There had been little struggle; the room was hardly disarranged at all. And it was unclear when the murder had taken place. There was a suggestion that the assistant, whose name was Mary, might have come back shortly afterwards – someone thought they had seen her in the street – but, if so, she had then fled rather than contact the police. Which was unfortunate, as the police never for a moment considered that she might have been responsible.

With her had gone the most valuable source of information, for she alone of the living might have known who had come that afternoon, at what time Madame Boninska had probably been killed and why. For nobody else had seen anything that day. And without her evidence there was no chance of solving the case. More alarmingly perhaps, I realised I had given Lady Ravenscliff some slightly inaccurate information: Madame Boninska had been found two days after her husband fell from his window, but the police doctors were not at all certain when she had actually been killed. The degree of uncertainty meant it could have been before Ravenscliff had dropped from the window, perhaps after. The police had concentrated their limited efforts on finding Mary, who was the only one who could enlighten them and, when they proved unsuccessful, had more or less given up. Their collective opinion was that she would turn up eventually, and they could reopen the case when she did. Until then, they had other things to worry about.

I had not been excessively diligent. Murders are rare, and it did have some of the exotic characteristics which turn a squalid death into an interesting story, but in general we follow the police lead unless there is good reason not to do so. In this case, the official reasoning seemed sound. The girl was crucial and there was not much to be done until she rematerialised. I wrote a sidebar on mediums and a piece on the fashion for the occult while I waited for some development, but could push it no further. If they couldn't find her, there wasn't much chance I could, and I did not have the leisure to try.

Now I did, and I also had a very much better reason to do so than a few column inches in the Chronicle. So I prepared to do all those reporterly things that I had omitted first time round.

The first thing was to talk to the neighbours. The police had already done that, and I had seen their notes one night in the pub, but I was now interested in different questions. They had asked if anyone had been seen arriving or leaving on the day of the murder. To which the answer had been no; no one in particular. But I was now interested in two days previously as well, when Ravenscliff's diary said he had an appointment. This wasn't likely to lead to much, but I wanted confirmation that he had gone there.

So I called in at the umbrella shop, as the proprietor had been the most useful of interviewees to the police, and I hoped he would prove the same for me. He was the only person, in fact, who had noticed anything at all, and had been the one who had discovered the body. It was rent day, and he had gone to collect. As the lady was too uninterested in the material things of this world to take the mundane matter of paying debts too seriously, he had refused to go away, kept on knocking and had eventually gone in. She apparently had something of a history of pretending to be out when he came to call, and she was three months in arrears.

Mr Philpot was the sort of man who had no first name. The sort whose wife addresses him as Mr Philpot after they have finished making love, if they ever do. He is the butt of jokes from his betters, who scorn his ilk for their respectability, and lack of imagination and utter dullness. The very epitome of the English lower middle classes; a shopkeeper, with standards to maintain and a small place in society to defend. I liked him; I have always liked the Philpots of this world, with their honesty and trustworthiness and decency. I even like their small-mindedness, for they are content with what is theirs, and proud of the little they have. Only if that is threatened do they become testy, but what group of mankind does not? They respect their betters, and fear those below them. They go to church and reverence the King, and sweep the pavement outside their shops every morning. All they want is to be left alone, and in return they provide the nation with all of its substance and solidity. If a factory worker kills his wife, or an aristocrat fathers a child, it is scarcely remarked upon; if a Philpot does so, it is a shock. Philpots are held to higher standards than most of mankind, and on the whole they live up to them.

So, I was predisposed to like Mr Philpot, in his neat waistcoat, with the armbands keeping the cuffs of his glistening white shirt out of harm's way. With his meticulous little moustache, and well-trimmed fingernails, and shining black shoes. And to like his shop, with its hundreds and hundreds of umbrellas, every single one of them black, with only the handles – each one pointing outwards like a row of grenadier guards on display – allowing just the slightest hint of flamboyance to brighten up the dark oak of the counters and floor. Philpot made me feel as though the world was in good hands. Until I met Elizabeth, I had taken it for granted that I should, eventually, marry the daughter of a Philpot, who would be as diligent in the home as her father was at work.

We talked for some time before I introduced the subject of his erstwhile tenant. It is always best to do so, if possible; to establish your credentials as a decent, upright man. I sympathised with his embarrassment, and consternation at suddenly finding his shop mentioned in the newspapers in connection with such a terrible event. The shame of the neighbours discovering that he had rented out his little flat to a charlatan and a prostitute. It might be that eventually he would live it down, but his good name had been tainted.

'And I only let her have the place out of the goodness of my heart,' he protested. 'I couldn't see anyone else renting her anything, and she pleaded with me not to throw her out when I discovered what she was up to. When I let her have it, I never dreamt for a moment there might be anything improper about her. She was an old woman. I felt sorry for her. I won't make that mistake again, let me tell you.'