It is now beholden on me to explore my friend's consumption of numerous narcotics and stimulants. I explained his habit in The Sign of Four, but there are episodes on which it is my duty to provide details. Of particular interest are the many unwholesome wretches Holmes cultivated whilst scouring the city.
Prominent amongst these was 'The Boss', Belsize Park, whose Haverstock Hill opium emporium was the nearest such outlet to Baker Street, and thus more convenient than the Limehouse den mentioned by Holmes in our last adventure.
Boss was nominally a shabby schoolman, tutoring pale youths from the seedier districts of Camden and Kentish Towns. His own addiction was to the street food available there – consumed in the company of tattered-clothed boys – none of whose clothing was in that state before they made his acquaintance.
A graduate of Bangor University, he taught both in the classroom and on the sports field. Working as a games master allowed him to freely indulge in his crimes, making indiscreet daguerreotypes of scantily clad youths for sale to London's underbelly of prowling perverts.
Holmes was of course monitoring these extra-curricular activities, all the while enthusiastically consuming his oriental pipes. It was regarding the former that one pleasant spring evening found us heading up Haverstock Hill.
If one has never kicked down a door, the first time provides a rush of excitement and satisfaction even Dr Freud would struggle to explain. The sturdier and more prosperous the entrance, the more thrilling it becomes. Both myself and Holmes beamed with boyish joy as we booted in the quivering black panels, less concerned with gaining entry than in outraging the Boss by waking his neighbours.
Eventually a large gap appeared, containing a cannon-ball head.
'Mr Holmes! You know my hours of entertainment. Whatever your needs, I will not tolerate such uncouthness in this respectable neighbourhood.'
'The same delightful one which housed the late Charles Augustus Milverton? Open up immediately Boss, unless you wish to suffer his fate!'
The battered door swung open and we rushed in.
Holmes was a master pugilist, even without his beloved knuckle-duster. Armed with it, he was more lethal than a Mohammedan force-fed pork scratchings.
'Now Boss, you are to desist from your disgusting pedagogy, or I shall return with a home-delivery of my main course: raw beef in all its sanguinary glory!'
The dazed Boss spat out several of his teeth but remained silent.
'I need the names of your co-conspirators in this board-school scandal, a list of those befouling the beacon lights of youthful advancement to satisfy their sordid depravities.'
Our host was dressed as if in tribute to the late Jimmy Savile: lurid burgundy shell-suit, dangling medallion – a fake medal from the recent Afghan campaign – and hair dyed nicotine yellow. As a wounded Kabul veteran, I ripped the bogus decoration from his neck then added a hefty knee in the bollocks to his recent discomforts.
Boss eventually produced a tomato-ketchup bespattered list of 'customers', for his vile prints.
'As I suspected,' murmured Holmes, 'this coincides with many of my dealers in recreational substances.'
I was unsurprised at Holmes' frank admission.
'The game's afoot, Watson! We venture into the wilds of south London – Clapham, to be precise.'
'Pray God Mr Holmes, you surely don't intend to confront Brixton Breath?'
'Indeed I do, Boss. Have your stableman get a horse and trap readied. We intend to travel under your livery colours!'
More able chroniclers than I have explored the marked differences between north and south London. Crossing the river, one enters at once more open yet less navigable territory, lacking apparent focus or landmarks. Of particular note are the many Commons dotted throughout this random sprawl.
One such is Clapham. The wide expanse was still peopled by occasional figures, no doubt making the most of a mild evening. As ever, Holmes seemed to know immediately where we were heading. Leaving the carriage by some ornamental park gates, we walked into its very centre.
Holmes held up his right hand and I knew to crouch behind the nearest tree.
Stood just yards from us in deepest conversation were an unlikely pair of strollers. A huge Rasta dwarfed a diminutive Welshman.
'Brixton Breath is selling his wares,' Holmes whispered. 'If it's one of the Boss' prints, we shall pounce'. He was still wearing the knuckle-duster, freshly flecked with the latter's blood from his punishment beating.
But nothing changed hands.
'At a dinner party with boyish entertainments? Well, I'll need this to be discrete; just call me Rod in front of them.'
The Rasta nodded back at the man, putting an arm around him. The unlikely pair then wandered off, unaware that we were following. A glinting hand was then dug into the small of his back. He was now a hostage, in the tender-care of Brixton Breath!
As always in London, neighbourhoods change with the crossing of a street. After twenty minutes, we entered the badlands of Brixton then Stockwell, towering blocks alternating with regenerated rows of Victorian houses. Brixton Breath forcefully led the man into one particularly stark monolith; I could read terror in his every faltering step.
We held back as he was pushed towards a vandalised lift. Holmes clearly feared precipitate action would risk the man's life.
'What a charming location for that most splendid of repasts: the south London dinner and drugs party!' My friend was in his most acerbic of moods.
We stayed in observation for over an hour, concealed behind utility shedding. Then I rubbed my bleary eyes in utter astonishment. Standing in the stairwell was our Welshman, 'stark-bollock naked' as Mr Henry James would say. He cut a pathetic figure, mercilessly lit in the fluorescent lighting, piles of mutton-fat flesh exposed to any in south London who should chance to pass.
'Robbed, robbed, robbed!'
Holmes rushed forwards and threw his cape over the shivering figure.
'Sir, such immodesty ill becomes this neighbourhood!'
'I have been robbed and stripped at knifepoint! What more have I to lose?'
A swift exit took us back to Clapham Common and the Boss' carriage. In no time, we had the man safely ensconced beside a roaring Baker Street fire, recounting his extraordinary tale.
'Mr Holmes, I am an esteemed Member of Parliament who found himself at a loss for company in this city. Somehow, I found myself wandering in a local park and happened to encounter a charming Caribbean gentleman who – discerning my vacant mood – invited me to a late-supper in his nearby flat.'
Holmes could hardly contain his mirth at this preposterous yarn.
'Pray continue. Both myself and Watson are long experienced in the most outlandish of tales!'
'No sooner had I accepted than I felt a knife dug into my lower back. I was rudely marched, on pain of instant death, into the very depths of the night. Somehow, I found myself in a grimy flat where I was relieved of phone, cards, pin-numbers and £1,000 in cash.
'I was then stripped naked and thrust into an echoing Stockwell stairwell, where I was fortunate indeed to encounter yourself and Dr Watson.'
'It is a most remarkable story. I have only heard of one similar case, which involved a distinguished member of the Brazilian political class, in a park well-known to Sao Paulo residents for strolls by gents late at night. I have just one question to ask, if you will permit me?'
'Of course, Mr Holmes, I am in your debt for rescuing me from an innocent misunderstanding.'
'What was dinner like?'
My friend collapsed into childish hysterics, which I found it impossible to resist joining.
'Anyhow, I know exactly the man to assist with your nightly needs and help in any scandal that may engulf a public figure like yourself. My brother Mycroft will be delighted to offer both accommodation and company on any further nocturnal perambulations.'
Months later, I read of his unfortunate arrest whilst 'badger spotting' in some woodland near an M4 service-station. The police – and his constituents – were baffled as to why he seemed more interested in the many parked cars and was again found wandering 'in a state of considerable undress'.