At the next corner I was nearer him, near enough to distinguish that he crossed the road and suddenly turned along the pavement to the right. We were evidently going in the direction of Fitzroy Square, though in which street I had no idea. In fear lest his quick ears should detect that I was following, I fell back a little, allowing him to get further in front. The houses we were then passing were good-sized private ones interspersed with shops, substantial houses of the usual style found in the decayed districts of London, dark, gloomy, and mysterious-looking. I recognised that we were in Cleveland Street. Then we turned again-- the first turning on the left round the corner by a laundry. Of a sudden I heard Kirk halt, as though in doubt. It seemed as though he was retracing his steps, having passed the house of which he was in search. Quick as thought, in order to avoid meeting him face to face, I stepped off the kerb into the roadway. He passed by within a few yards of me, yet entirely unconscious of my proximity. Then he repassed, as though having satisfied himself that he had not yet reached his goal. In a London fog, one house is very much like another, especially in a side street. In the distance I saw a red glimmer--the light of a surgery. Two dark, evil-looking men lurched past me, and then a woman, half-drunken and reeling. For a few seconds I lost his footsteps, but again they reached my ears. The sound was a different one. He had ascended one of the flights of steps! I hurried forward, but as I did so I heard a door close sharply. He had entered one of those dark houses, but which of four or five I was, unfortunately, utterly at a loss to decide. The exterior of each I examined carefully, taking note of their number. In two of them yellow gas-jets were burning over the grimy fanlights, throwing out a faint light into the pall of the fog, while in one a light was burning in the front room of the ground floor. All were let in squalid apartments, for there seemed a general frowsiness about that undesirable neighbourhood, where the greater part of the inhabitants were foreigners of the working class. Each house, with its railings and deep area, had but little to distinguish it from its neighbours, all were dirty, neglected, and forbidding in that darkness and gloom. I stood in chagrin at having thus lost sight of my mysterious friend, and could only wait for his exit. Two of the houses were within the zone of the weak light thrown by the street-lamp; the other three were in obscurity. In one of them--which one I knew not--Kershaw Kirk had kept an appointment, arranged, perhaps, by that signal which he had made by the raising and lowering of the blind. My position was most tantalising, yet I felt that if I remained there on watch I should most certainly see him come out, and then at least know the number of the one he had visited.