I realise that to a great many of my readers my reputation has written me as the most patient and tolerant of fellows; never one to become so exasperated over a mere trifle, or perturbed over a small nothing. To an extent I suppose this must be true, and yet my dear friend, the great Sherlock Holmes, swears it absolutely to be otherwise.

But then, of course, he would.

I should have known better than to offer my assistance towards the issue solemnly at hand.

Of course, I knew no better, and I blundered blindly in.

Holmes and I were seated by the fire one damp and foggy morning in October. He was occupied with his notebook and pen, while I was satisfied with my pipe and daydreams. I was a little startled, therefore, when my friend slapped his notebook shut and threw himself back into his armchair with a mewl of discontent.

"What is the matter?" I enquired.

"Hnf," grumbled Sherlock Holmes.

"'Hnf'? Does that bear translation?"

"It bears no translation except 'Hnf'," replied he, stretching his legs out before him and dropping his arms to hang loose over the sides of the chair. "Watson, I fear that I have come up against the most appalling stumbling block."

"Oh dear," I said. "What is the stumbling block, and why ever does it make you say 'Hnf'?"

"It is the Merryweather case," said he. "I have reached a point in my investigation whereby it seems necessary for me to tail this objectionable fellow as he goes about his ridiculously convoluted day. It may only take a morning or heaven forbid an entire week, but tail him I absolutely must."

"I do not see the problem," I said. "So tail him, then."

Holmes tutted. "Well, he travels by dog-cart. I have no great desire to wear myself ragged, running behind him like a red-faced lunatic for miles on end. Furthermore, I refuse to bicycle. The London roads are obliterated by pot-holes and I would surely find myself somersaulted over the handlebars every two hundred yards."

I shook my head. "I still fail to grasp the difficulty here. You might hire a hansom?"

"For all of the day, over possible multiple days? Too expensive, Watson."

"See if your brother Mycroft might lend you the use of his carriage?"

"Ha! Ha! Ha!"

"Very well, then, don't." I sighed and relit my extinguished pipe. "Hire a small dog-cart of your own to follow the fellow. I imagine that would be a great deal more economical than employing a driver along with it."

Holmes's face twisted into a swift half dozen expressions of lesser and greater torture. After a smaller number of seconds it fell into a semi-repose and he fixed his grey stare upon me, his thin fingers drumming upon the brocaded cushions.

"Watson, I would surely do it, but for the unfortunate fact that I cannot drive."

I blinked. My eyebrows rose and fell and rose again. My mouth opened to begin a sentence and then shut fast to better formulate its response.

"What do you mean?" I said, eventually.

I acknowledge that it might not have been my most eloquent rejoinder.

"I never learned how to," my friend replied, defiantly. "I do not care for horses, Watson. They have big teeth. They snort. They do a lot of... the other thing... at the other end." He shuddered. "And they do not seem to care for me," he added as an afterthought, sounding a little aggrieved about it now. "So it would appear that I am stymied."

"You should not let that stop you," I said, encouragingly. "It is not as if you would be tap-dancing upon its back. You would be seated safe upon the dog-cart."

Here, alas, it was, that I made my gravest error.

"I learned to drive many years ago," I said. "I can show you, if you'd like."

Holmes regarded me, intently curious.

"I was not aware that you could drive," he said, in a tone of reverent wonder.

"Yes," I replied, my ego inflated and my chest rising to meet it. "My family possessed a small carriage for our own daily use, and Chester did very well at pulling it."

"Your... father... was named Chester?"

"No, Holmes, the horse was."

"Well, might we borrow the venerable Chester and his carriage, then, for, shall we say, all of next week?"

"Holmes, really, that was twenty years ago, my dear fellow. Chester and the carriage are no more. We must source another vehicle."

Holmes had raised himself in some eagerness from his recline, but now he slumped back into the plush with a thwarted groan.

"Watson, why must you make everything so difficult? Why did you promise me a Chester if there is now nothing left of him?"

I clapped my hand to my forehead. "I did not promise you a Chester. I was simply reminiscing about – oh never mind, dash it all." I stood up. "I am going out," I said, my head spinning only but a slight fraction. "I intend to visit my friend Witters, who I know owns such a cart and animal as we require, and I shall ask for his indulgence with it for a few days."

"Ask him if we can borrow it as well."

"That is what I meant, for the love of my sanity, Holmes..."

I caught up my hat and coat and departed from our rooms before I heard my friend's reply. I went to pay call upon Witters.

Two days later we had taken temporary possession of a chestnut horse and smart two-wheeler, and were seated side by side upon it, my friend in his anticipatory nerves at the rein board.

"This is complicated," said Holmes, gazing down in dismay at the leather formation he was now grasping. "It is like playing cat's cradle."

I chuckled. "It seems a little like that at first, but you'll get used to it."

I leaned across to Holmes's side and began to explain a little of the spanning of the reins, of locking, shortening and lengthening. He listened to my instruction most intently, nodding all the while, grunting in the affirmative at my occasional enquiry as to whether everything was clear. Eventually, satisfied, I sat back from my tutorial. My friend appeared suddenly anxious, darting glances first to me then back to his hands.

"I didn't understand any of that," said he. "Would you mind terribly repeating it over?"

"But you were nodding! And agreeing with me!"

"I may have been nodding and agreeing," replied Holmes with some asperity, "but that should not necessarily be taken to mean that I understood what was being said."

"I see that now," I said, my eyebrows knotted. I carefully repeated the prepared lesson, re-covering several points many times at my friend's request.

"All good?" I asked, some twenty minutes later.

"Yes," said he. He bounced up and down in his seat. "Are we ready, then?"

"As you like," I said. "Holmes, please, do be careful and take it slowly to begin with."

With a brisk clip of the reins the horse stirred into forward motion, and the cart commenced to crawl. We manoeuvred Baker Street and its surrounds competently, more or less, and I was beginning almost to relax when we emerged out onto a broader stretch of tarmacadam.

"How do I make this thing go faster?" asked Holmes. "Is there a word that I should shout?" He inclined his head and shoulders towards the trotting beast. "Hoopla! Alley-oop!" He rattled at the reins in childish frustration.

I shook my head at him. "Your cat-calling won't do the slightest bit of good, Holmes. The horse will only respond to – Oh my goodness..."

By some persuasive means, some lucky fortune with the handling, my friend had urged the willing horse to break into a gallop, and we were now fairly speeding down the Tapfinch Road. I clung on to my seat, and turned to look at Holmes. His expression was that of adrenalin fuelled glee; his head thrown back, he was cackling to the wind. He caught my anguished glance and returned a wink.

"I say! This is rather better than I imagined!" he chirruped. "Wait, Watson, where is the honker?"

"Where is the what?" I shouted, over the clattering of hooves.

"The honker, the bell that tells people to get out of the – Get out of the way!" he shrieked suddenly, to a small cluster of pedestrians who were at that instant regrettably attempting to cross from one side of the road to the safety of the other. With alarmed faces, gestures and squeals, they scattered. The dog-cart ploughed on its way.

"That was close," said Holmes.

I held on to my hat with one hand; with the other I swiped a remonstrance upon my friend's shoulder.

"Stop!" I commanded, with all the vigour I was capable of mustering. "Stop the cart this instant, Holmes! You are an absolute menace."

"Don't blame me, blame the silly horse," he replied, with a hurt look. "And these confounded reins," he added. "Watson, I forgot what it was that they all do again?"

"Move over!"

"But we're in mid-"

"Move over, Holmes, or my word, I shall have to knock you into the gutter."

The cart, all this time, was lurching to the left and to the right, the poor animal evidently confused by the instruction from its driver. I saw to my great horror a number of people turn to stare at us as we flashed by, and prayed that we should not be recognised by any of them. I snatched at the reins (I was by now almost sat in my friend's lap, for he was rigidly reluctant to let them go), and succeeded in slowing the horse to the point where I might draw it up to the kerb.

I took a deep breath and sat back in my seat.

"Great heavens," I said, rubbing my face. "We might have killed someone with the way that you were driving, Holmes."

"Nonsense," said my friend. "You are such a spoilsport, Watson. I was just beginning to enjoy myself. Where is the honker, by the way?"

"You are the honker," I said, exasperated. "The greatest honker that I have ever known, I do declare it. You cannot possibly be entrusted with this cart all by yourself, my dear fellow. You do realise?"

He pouted and made as if to argue, then surrendered.

"I suppose," said he, his lips pursed. "But what shall I do? Merryweather must be tailed and I refuse to ride a blasted bicycle, and I simply cannot -"

"I shall drive you where you wish to go," I said, closing my eyes in resignation. "We shall tail Merryweather together, and at least that way I shall know that you are still alive and not mangled beneath the wheels of an overturned and shattered dog-cart."

"Oh, Watson," said he, quite moved and much cheered. "Thank you. You always come to my rescue, and for that I am very grateful. But my goodness, it is as well that you were never a schoolteacher, for you are the most impatient fellow that ever lived or breathed."

"Move over, Holmes," I said, my teeth gritted, my lips contorted into a fond smile. "Do move over, now, there's a good man."