“I shall have to remind you of this,” I remarked with a chuckle. “You have often said that the official force can scarcely ever be trusted to do the right thing, but it seems that in this case at least they were, by your own admission, entirely correct.”

“Perhaps so,” returned my friend, “but they had received some material assistance. The man they arrested had already made a full confession of his part in the affair before the police even arrived. It would therefore have been somewhat difficult for them not to have identified the villain. For all the intellect involved, Scotland Yard might as well have sent a pair of Trafalgar Square pigeons down to Norwood. They would probably have managed the matter just as successfully, and would certainly have arrived somewhat sooner. In short, Watson, I have had no worthwhile case all week, and time lies heavy upon my hands.”

“It may be that your practice is following the pattern of most medical practices,” I observed, laughing. “One old physician for whom I worked for a few months while a student never ceased to lament how the arrival of fine weather always brought a severe decrease in the numbers of his patients.”

My friend nodded. “Perhaps it is. But sometimes it seems that the present age has abandoned altogether the production of interesting mysteries. I have therefore been occupying my all too abundant leisure time in working back through those of past centuries. At my present rate of progress, I should soon be on to the cave murders of the Stone Age.”

I laughed. “Perhaps your missing clients will all turn up together one rainy day, as tends to happen in a doctor’s practice.”

“I rather doubt it,” responded Holmes with a dry chuckle. “Anyhow, I have now abandoned all hope that any clients will appear this week, and can only hope that next week will show an increase in business!”

As it happened, however, my friend was on this occasion mistaken, and his despair premature. Scarcely five minutes after he had uttered these words our conversation was interrupted by the mad jangling of the front-door bell.

“What an impatient caller!” I remarked, as the wild ringing of the bell continued in an unbroken clamour.

“It is a client, or I am much mistaken!” cried Holmes in delight, springing to his feet and clapping his hands together. “I recognize the symptoms. Let us clear away this litter you have left, Watson,” he continued, picking up the day’s newspapers, which were scattered upon the floor beside his chair, and tossing them into a corner.

A moment later, our landlady appeared with a card upon a salver. “Mr Henry Claydon to see you, Mr Holmes,” said she.

“Ask him to step up, Mrs Hudson,” responded Holmes, but scarcely were the words out of his mouth when there came a rapid drumming of footsteps upon the stair. Moments later, a young man, breathless and frantic-looking, appeared behind the landlady and, without further ceremony, edged his way into the room. Though he was dressed in the smart clothes of a City man, they were dishevelled and grubby looking. He had a black eye, there was blood upon his face, and the bowler hat he carried in his hand was in a sorry, crumpled state.

“Pray excuse my abrupt entry,” cried he, “but my situation is desperate.” Behind him, Mrs Hudson closed the door quietly, an expression of disapproval upon her face. “Mr Holmes!” he continued with a cry, rushing suddenly forward and grasping my hand. “You cannot imagine the terrible thing that has happened!”

“I am sorry, but you are under a misapprehension,” I interrupted, shaking my head. “I am not Sherlock Holmes.”

“What!” cried he, springing back as if he had received an electric shock from touching my hand. “Oh, no!” he continued in a wailing tone, clutching the sides of his head, as if in great pain. “Don’t say it is happening again!” With a vigour that was alarming to witness, he abruptly cast himself down to the floor with a cry of, “Madness! Madness! All is madness!”

“My dear sir,” said Holmes in an anxious voice. “Pray be calmed. I am the man you seek. I am Sherlock Holmes.”

“You are?” cried the other, abruptly ceasing his moaning and looking up. “You really are? Why, then, you at least are where you are supposed to be. The Lord be praised!”

“It is clear you have suffered some misfortune,” said Holmes in a measured tone. “If you will take a seat and tell us about it, perhaps we can be of assistance.”

“Misfortune?” cried our visitor, rising to his feet and dusting himself off. “Ha! What I have suffered, Mr Holmes, is a unique and terrible experience. Why, sir, it knocks all other mysteries of the world into a cocked hat.”

“Pray, let us have the details.”

“Certainly,” returned the other, who appeared a little calmed by Holmes’s soothing manner. “Some men, as you know, have their pockets picked in the street, and lose their watches. Other men have their houses broken into and lose the odd candlestick or two. I have lost to a thief something far greater in every sense than these trifles.”

“Pray be precise.”

“Gentlemen, while I was at work today, thieves have been busy in Kendal Terrace, North Clapham, where I have lived happily for six weeks. I returned home this evening to find that my house has been completely stolen away!”

“What!” cried Holmes and I as one.

“You see?” said our visitor, a note of satisfaction in his voice at our surprise. “It is enough to drive a man insane!”

“But surely,” I suggested, “you have made a mistake? Surely, if your house does not appear to be there, you have simply turned inadvertently into the wrong street? Many suburban streets in London are of very similar appearance. Might you not simply have confused one street with another?”

“Certainly not!” retorted Claydon. “I think I know my own street well enough, thank you, though I have lived in it but a little while. Besides, I could see through the parlour window of the house that my furniture was still in place.”

“Ah!” said Holmes. “I see. So the house itself has not disappeared? It is still there?”

“Certainly.”

“But it is now occupied by someone else?”

“Precisely.”

A look of intense disappointment came over Holmes’s features at this mundane explanation of what had promised to be a more outré mystery. “Is it not possible,” said he, “that there has merely been some sort of confusion over the letting arrangements? Perhaps, under the misapprehension that you have moved out, the agents have given a key of the house to someone else, so that they can look it over. I recommend that you speak to your landlord on the matter, Mr Claydon.”

“No! No, no!” cried Claydon in protest, springing to his feet and shaking his head wildly. “You do not understand! The people in my house are not simply looking it over, they are living there as if they have always done so, and as if my own memory of living there is nothing but a pitiful delusion! And nor is the presence of these strangers in my house the only amazing thing: there is also the question of where my own household has vanished to. Where is my wife? Where are the servants?”

“What sort of people are these strangers?” asked Holmes after a moment. “Are they vagabonds, or otherwise disreputable?”

“Absolutely not,” returned Claydon emphatically, resuming his seat. “On the contrary, they appeared highly respectable. That is what is so amazing! The lady of the house came to the door eventually, after I had been haggling for some time with a maid who would not let me in, and she was, I must say, very well spoken. She was highly indignant when I insisted that I lived there, and expressed herself most forcefully upon the point, but never ceased to be ladylike, if you know what I mean.”

“Did you consider calling a policeman to assist you?”

“I had no need. The lady of the house – the lady of my house, I should say – called one herself, and he threatened to arrest me if I didn’t clear off!”