A solicitor of an active habit and athletic tastes who is compelled by his hopes of business to remain within the four walls of his office from ten till five must take what exercise he can in the evenings. Hence it was that I was in the habit of indulging in very long nocturnal excursions, in which I sought the heights of Hampstead and Highgate in order to cleanse my system from the impure air of Abchurch Lane. It was in the course of one of these aimless rambles that I first met Felix Stanniford, and so led up to what has been the most extraordinary adventure of my lifetime. One evening--it was in April or early May of the year 1894--I made my way to the extreme northern fringe of London, and was walking down one of those fine avenues of high brick villas which the huge city is for ever pushing farther and farther out into the country. It was a fine, clear spring night, the moon was shining out of an unclouded sky, and I, having already left many miles behind me, was inclined to walk slowly and look about me. In this contemplative mood, my attention was arrested by one of the houses which I was passing. It was a very large building, standing in its own grounds, a little back from the road. It was modern in appearance, and yet it was far less so than its neighbours, all of which were crudely and painfully new. Their symmetrical line was broken by the gap caused by the laurel-studded lawn, with the great, dark, gloomy house looming at the back of it. Evidently it had been the country retreat of some wealthy merchant, built perhaps when the nearest street was a mile off, and now gradually overtaken and surrounded by the red brick tentacles of the London octopus. The next stage, I reflected, would be its digestion and absorption, so that the cheap builder might rear a dozen eighty-pound-a-year villas upon the garden frontage. And then, as all this passed vaguely through my mind, an incident occurred which brought my thoughts into quite another channel. A four-wheeled cab, that opprobium of London, was coming jolting and creaking in one direction, while in the other there was a yellow glare from the lamp of a cyclist. They were the only moving objects in the whole long, moonlit road, and yet they crashed into each other with that malignant accuracy which brings two ocean liners together in the broad waste of the Atlantic. It was the cyclist's fault. He tried to cross in front of the cab, miscalculated his distance, and was knocked sprawling by the horse's shoulder. He rose, snarling; the cabman swore back at him, and then, realising that his number had not yet been taken, lashed his horse and lumbered off. The cyclist caught at the handles of his prostrate machine, and then suddenly sat down with a groan. "Oh, Lord!" he said. I ran across the road to his side. "Any harm done?" I asked. "It's my ankle," said he. "Only a twist, I think; but it's pretty painful. Just give me your hand, will you?"