Such was the remarkable narrative to which I listened on that April evening --a narrative which would have been utterly incredible to me had it not been confirmed by the actual sight of the tall, spare figure and the keen, eager face, which I had never thought to see again. In some manner he had learned of my own sad bereavement, and his sympathy was shown in his manner rather than in his words. "Work is the best antidote to sorrow, my dear Watson," said he; "and I have a piece of work for us both to-night which, if we can bring it to a successful conclusion, will in itself justify a man's life on this planet." In vain I begged him to tell me more. "You will hear and see enough before morning," he answered. "We have three years of the past to discuss. Let that suffice until half-past nine, when we start upon the notable adventure of the empty house."

It was indeed like old times when, at that hour, I found myself seated beside him in a hansom, my revolver in my pocket, and the thrill of adventure in my heart. Holmes was cold and stern and silent. As the gleam of the street-lamps flashed upon his austere features, I saw that his brows were drawn down in thought and his thin lips compressed. I knew not what wild beast we were about to hunt down in the dark jungle of criminal London, but I was well assured, from the bearing of this master huntsman, that the adventure was a most grave one--while the sardonic smile which occasionally broke through his ascetic gloom boded little good for the object of our quest.

I had imagined that we were bound for Baker Street, but Holmes stopped the cab at the corner of Cavendish Square. I observed that as he stepped out he gave a most searching glance to right and left, and at every subsequent street corner he took the utmost pains to assure that he was not followed.

Our route was certainly a singular one. Holmes's knowledge of the byways of London was extraordinary, and on this occasion he passed rapidly and with an assured step through a network of mews and stables, the very existence of which I had never known. We emerged at last into a small road, lined with old, gloomy houses, which led us into Manchester Street, and so to Blandford Street. Here he turned swiftly down a narrow passage, passed through a wooden gate into a deserted yard, and then opened with a key the back door of a house. We entered together, and he closed it behind us.

The place was pitch dark, but it was evident to me that it was an empty house. Our feet creaked and crackled over the bare planking, and my outstretched hand touched a wall from which the paper was hanging in ribbons.

Holmes's cold, thin fingers closed round my wrist and led me forward down a long hall, until I dimly saw the murky fanlight over the door. Here Holmes turned suddenly to the right, and we found ourselves in a large, square, empty room, heavily shadowed in the corners, but faintly lit in the centre from the lights of the street beyond. There was no lamp near, and the window was thick with dust, so that we could only just discern each other's figures within. My companion put his hand upon my shoulder and his lips close to my ear.

"Do you know where we are?" he whispered.

"Surely that is Baker Street," I answered, staring through the dim window.

"Exactly. We are in Camden House, which stands opposite to our own old quarters."

Retrace Sherlock Holmes’ and Dr Watson’s singular route from Oxford Circus via Cavendish Square to Baker Street with Detective Walks.