To those who have never attempted to track a fellow creature surreptitiously through the streets of London on a hot day, the feat may appear simple. It is in reality a most exhausting, dilatory, and humiliating exercise. Our difficulty lay not so much in keeping our friend in sight as in avoiding frequent and unexpected collisions with him. The general idea, as they say on field days, was to keep about twenty yards behind him; but under certain circumstances distance has an uncanny habit of annihilating itself. The man himself was no hustler. Once or twice he stopped to light his pipe or converse with a friend. During these interludes Stella and I loafed guiltily on the pavement, pointing out to one another objects of local interest with the fatuous officiousness of people in the foreground of hotel advertisements. Occasionally he paused to contemplate the contents of a shop window. We gazed industriously into the window next door. Our first window, I recollect, was an undertaker's, with ready-printed expressions of grief for sale on white porcelain disks. We had time to read them all. The next was a butcher's. Here we stayed, perforce, so long that the proprietor, who was of the tribe that disposes of its wares almost entirely by personal canvass, came out into the street and endeavored to sell us a bullock's heart. Our quarry's next proceeding was to dive into a public house. We turned and surveyed one another. "What are we to do now?" inquired my wife. "Go inside, too," I replied with more enthusiasm than I had hitherto displayed. "At least, I think I ought to. You can please yourself." "I will not be left in the street," said Stella firmly. "We must just wait here together until he comes out." "There may be another exit," I objected. "We had better go in. I shall take something, just to keep up appearances; and you must sit down in the ladies' bar, or the snug, or whatever they call it." "Certainly not!" said Stella. We had arrived at this _impasse_ when the man suddenly reappeared, wiping his mouth. Instantly and silently we fell in behind him. For the first time the man appeared to notice our presence. He regarded us curiously, with a faint gleam of recognition in his eyes, and then set off down the street at a good pace. We followed, panting. Once or twice he looked back over his shoulder a little apprehensively, I thought. But we ploughed on. "We ought to get there soon at this pace," I gasped. "Hello! He's gone again!" "He turned down to the right," said Stella excitedly. The lust of the chase was fairly on us now. We swung eagerly round the corner into a quiet by-street. Our man was nowhere to be seen and the street was almost empty. "Come on!" said Stella. "He may have turned in somewhere."