A Chinese “boy” of indeterminable age, wearing a slop-shop suit and a cap, was waiting outside the door, and when Sin Sin Wa appeared, carefully locking up, he muttered something rapidly in his own sibilant language.

Sin Sin Wa made no reply.  To his indoor attire he had added a pea-jacket and a bowler hat; and the oddly assorted trio set off westward, following the bank of the Thames in the direction of Limehouse Basin.  The narrow, ill-lighted streets were quite deserted, but from the river and the riverside arose that ceaseless jangle of industry which belongs to the great port of London.  On the Surrey shore whistles shrieked, and endless moving chains sent up their monstrous clangor into the night.  Human voices sometimes rose above the din of machinery.

In silence the three pursued their way, crossing inlets and circling around basins dimly divined, turning to the right into a lane flanked by high, eyeless walls, and again to the left, finally to emerge nearly opposite a dilapidated gateway giving access to a small wharf, on the rickety gates bills were posted announcing, “This Wharf to Let.”  The annexed building appeared to be a mere shell.  To the right again they turned, and once more to the left, halting before a two-story brick house which had apparently been converted into a barber’s shop.  In one of the grimy windows were some loose packets of cigarettes, a soapmaker’s advertisement, and a card: 

    Sam Tuk
    barber

Opening the door with a key which he carried, the boy admitted Sir Lucien and Sin Sin Wa to the dimly-lighted interior of a room the pretensions of which to be regarded as a shaving saloon were supported by the presence of two chairs, a filthy towel, and a broken mug.  Sin Sin Wa shuffled across to another door, and, followed by Sir Lucien, descended a stone stair to a little cellar apparently intended for storing coal.  A tin lamp stood upon the bottom step.

Removing the lamp from the step, Sin Sin Wa set it on the cellar floor, which was black with coal dust, then closed and bolted the door.  A heap of nondescript litter lay piled in a corner of the cellar.  This Sin Sin Wa disturbed sufficiently to reveal a movable slab in the roughly paved floor.  It was so ingeniously concealed by coal dust that one who had sought it unaided must have experienced great difficulty in detecting it.  Furthermore, it could only be raised in the following manner: 

A piece of strong iron wire, which lay among the other litter, was inserted in a narrow slot, apparently a crack in the stone.  About an inch of the end of the wire being bent outward to form a right angle, when the seemingly useless piece of scrap-iron had been thrust through the slab and turned, it formed a handle by means of which the trap could be raised.

Again Sin Sin Wa took up the lamp, placing it at the brink of the opening revealed.  A pair of wooden steps rested below, and Sir Lucien, who evidently was no stranger to the establishment, descended awkwardly, since there was barely room for a big man to pass.  He found himself in the mouth of a low passage, unpaved and shored up with rough timbers in the manner of a mine-working.  Sin Sin Wa followed with the lamp, drawing the slab down into its place behind him.