Through the weather-beaten gate which opened at intervals to admit the builders’ carts was Shadwick Lane. It had none of the picturesque character of the slum it used to be, when its houses were of wood, and water-butts stood in every backyard. Nowadays it consists of four walls, two on either side of the street. Bridging these is an inverted V of slate, which is called a roof, and at frequent intervals there are four red chimney-pots set on a small, square, brick tower. These denote roughly where lateral walls divide one hutch from another. Each partition is called a “house,” for which people pay rent when they can afford it. The walls which face the street have three windows and a doorway to each division. Joe Attymar’s house did not properly stand in the lane at all, and Shadwick Lane was only remotely interested in the barge-master, for the curious reason that he could reach his house and yard by Shadwick Passage, a tortuous alley that threaded a way between innumerable back-yards, and, under the shadow of a high warehouse, to Tooley Street. Year after year the swarthy man with the little iron-grey beard and the shaggy eyebrows brought his barge up the river, always with a cargo of bricks. And invariably the barge went down empty and without his presence--for, for some reason, there was neither passenger nor crew on the down-river trip. This fact was unknown to the people of Shadwick Lane. They were even unaware that Joe Attymar did not sleep in his house more than one night every month. They knew, of course, from the muddy old motor-car, that he drove through the wide gates occasionally, that he went abroad, but guessed that he was engaged in the legitimate business of lighterman. There are certain minor problems which from time to time cause the chiefs of Scotland Yard to move uneasily and impatiently in their padded chairs, and say to their immediate subordinates: “Do something.” Mr. Attymar, though he was blissfully unaware of the fact, was one of these minor problems. There are gaming houses which harass the police, queer little clubs, and other establishments less easy to write about in a reputable magazine, but Mr. Attymar was not associated with one of these. Such problems are, in one shape or another, perennial! Occasionally they grow acute, and just at that moment the question of systematic smuggling was worrying Scotland Yard considerably. Chief Constable Mason sent for Inspector Gaylor. “They’ve pulled in a fellow who was peddling dope in Lisle Street last night,” he said. “You might see him after his remand. I have an idea he will squeak.” But the man in question was no squeaker, though he had certainly given that impression when he was taken red-handed. He said enough, however, to the patient detective to suggest that he might say more.