The trouble began on a Wednesday eve in September – a day and month which carry no bearing whatsoever, other than the fact they are now seared, for better or worse, into my memory. My friend, the great detective Sherlock Holmes, had been in ill temper since the Monday. Close on the trail of Hoggerty (a man of most questionable memory), and several ambushes and wayward chases later, Holmes was barely any closer to the criminal's arrest.

"I can't understand it," said he, while sat in his chair by the fire, forlorn. "The fellow has pigeon toes, knock-knees and shingles. By rights he ought to be slower than a snail in molasses. Why can't I out-run him? Watson? Explain."

I felt put on the spot. I cleared my throat once or twice. "Well, my dear fellow, I imagine it might be because he is slighter than you?"

"Not at all. He is quite eleven pounds the heavier, and no taller."

"Then perhaps it is likely he has a sound knowledge of London, and therefore is more familiar with his escape routes than, er...?"

Here my friend snorted, and thumped on the arm of his chair.

"Perhaps not, then," I quickly amended. I improvised wildly: "Mr. Hoggerty is simply more aerodynamic?"

There was a silence while Sherlock Holmes digested this scrap of information.

"Aer-o-dy-nam-ic," he repeated, stretching out each syllable as if the word was entirely new to him and he was not sure of the taste of it. "Watson? Elaborate, please."

I was beginning to wish most heartily that my friend would stop his "Watson"-ing me with requests to explain and elaborate. I seldom had any idea of what I was talking about.

"Why don't you consult your good old Index?" I offered hopefully. I pretended to be busy with my shirt-cuff.

I heard Holmes sigh and scrabble at the bookshelf. He heaved down a monstrous tome and commenced to flick through many pages. He was momentarily distracted by Aardvarks, and loudly dismissive on the subject of Adler, Irene.

"Aer-o-dy-nam-ic!" he exclaimed at last, happily thrusting out a finger to a page I could not see.

The reading kept him busy for ten minutes, after which he became pensive and retired to his bedroom. From within I detected the sound of dresser drawers opening, closing, a faint metal clatter. I wondered what was happening. I supposed that I should know before too long.

It seemed as an eternity. I confess I fell asleep, and awoke some one hour, two hours later, with the room now bathed in gloom, the merest sliver of a lamp light shining through from Holmes's room. I heaved myself up from my chair and set to making light within the sitting-room.

"Holmes!" I called out. "Holmes, are you all right in there?"

A scuffling; a rusting squeak, which I recognised as the hinges of the full length angled mirror that Holmes kept in a corner of his room. Whatever was he doing?

Two minutes, more, ticked by, and then, the door swung halfway open. Holmes emerged. His expression was undefinable. A trifle horror-struck, perhaps, with a soupçon of fevered delight.

"Holmes?"

I was not sure what else to say.

"Watson," said he, tentative. "Watson, Watson, Watson."

We looked at one another.

"Holmes?"

This was a terrible conversation.

"Watson," said my friend, "I... did a thing."

I sat up straighter in my chair. "What did you do?"

I watched him walk across the room. The act of doing so made him giggle inexplicably. He stooped to retrieve his Index volume, and replaced it on the bookshelf. He turned to me. "I do not think that I can tell you."

A myriad of monstrous notions flashed their way across my mind.

"Holmes," I said beseechingly, "are you on some form of stimulant?"

This made him giggle all the more.

"I have made myself aerodynamic," said he.

And indeed, that was the most I could get out of him that evening. I retired to bed not a little irritated and perplexed. I resolved to reach the bottom of the mystery on the morrow.

The morrow, when it came, found me at the breakfast table. I had eaten all the bacon and three-quarters of the eggs when Holmes appeared. He sat down somewhat cautiously, nodding in my direction as he did so.

"Good morning, Holmes," I said, intensely curious, the more so now. "How are you feeling?"

"Feeling? Why? I'm fine," he snapped. "Absolutely hunky-dunky, thank you, Watson."

He took a piece of toast and stabbed it with a curl of butter. He paused to scratch his leg, smearing his trousers as he did so. He shifted in his seat; he shook his shoulders, set his jaw.

"Are you still aerodynamic?" I asked him. I really had to know the answer.

"Yes," said Holmes. "I think so. I will test out my theory later."

I stared, fascinated, as he dropped his toast and clawed with both his hands beneath the tablecloth.

"I'm a little itchy," he said sullenly, in answer to my eyebrows which had raised above my hairline.

"You have an allergy?" I was genuinely curious.

"No." Through tight-clenched teeth.

"You are wearing a new pair of trousers?" I chuckled. "If so, they are quite ruined, for you have covered them in butter."

"Yes, I know," said he. "And no. But drat it, Watson, you're making things worse."

"I wish that I knew exactly what I was making worse," I mused aloud. "I wish you'd tell me, Holmes."

My friend sighed explosively.

"I shaved my legs," he said abruptly. Then, to my astounded silence, clarified: "To make me aerodynamic, Watson, or have you not been paying any attention at all?"

Scratch, scratch.

"You shaved your legs," I responded, slowly. "All of them?"

"Well, I only have two legs," said he, confused.

"No, no," I said, "I meant, you have removed all the hair from every inch of both legs?"

Holmes looked away, uncomfortable. "Yes." He turned his head to me again. "To make me aerodynamic," he repeated, as if I were so incredibly dense.

"I see." Or at least, rather, I thought I did.

"No, you don't see," said Holmes. "That is exactly my point. I have done a very clever thing, which will help me to catch Hoggerty." He rubbed his hands together then. "He will be so surprised."

"Is that what your Index advised you to do?"

"More or less," my friend replied. "It may not have said exactly that, but I interpreted it as such. You TOLD me to look it up, Watson," he said then, accusingly. "So I don't understand why you're being so stupid." He scraped again at both thighs. "Oh bother and blast it, I really do itch."

"Forgive me," I said, "if I fail to see how you can be effectively aerodynamic through a pair of twill trousers." I thought for a moment. "Your theory might work very well, however, if the pair of you were garbed in swimming costumes, and you were cast into the middle of the Serpentine."

"That is not very likely to happen," said Holmes. His tone was now uncertain. "What is it you are trying to tell me? That I have shaved my legs for nothing?"

"I am afraid so, Holmes."

For a number of seconds his bottom lip trembled, and I wondered if he might be about to throw some sort of fit. To my astonishment, after the trembling, his face turned to smiles.

"Perhaps it is not such a waste," he replied. "Even if they itch, my legs look lovely with no hair on them." He sat back in his chair, and turned attention to his breakfast.

And so, then, that was it. At some juncture – two weeks later – the fellow Hoggerty was captured; if not aerodynamically, at least by a Scotland Yard inspector. Holmes remains quite taciturn on the subject of his legs, and perhaps that's for the best. He is scratching less, these days, at any rate.