They all walked in silence, and did not greet one another as they passed; some cast from time to time furtive looks behind them; but every one of these evening prowlers seemed to have the same objective, for as soon as they reached the crippled archway, they disappeared within the gloom of its yawning mouth. Anon when the police-patrol had gone by and was lost in the gloom there where Bath Street debouches on the river bank, two of these heavily cloaked figures walked rapidly down from the Strand, and like the others slipped quickly under the archway, and made straight for the narrow door on the left of the passage. This door was provided with a heavy bronze knocker, but strangely enough the newcomers did not avail themselves of its use, but rapped on the wooden panels with their knuckles, giving three successive raps at regular intervals. They were admitted almost immediately, the door seemingly opening of itself, and they quickly stepped across the threshold. Within the house was just as dark and gloomy as it was without, and as the two visitors entered, a voice came from out the shadows, and said, in a curious monotone and with strange irrelevance: "The hour is late!" "And 'twill be later still," replied one of the newcomers. "Yet the cuckoo hath not called," retorted the voice. "Nor is the ferret on the prowl," was the enigmatic reply. Whereupon the voice speaking in more natural tones added sententiously: "Two flights of steps, and 'ware the seventeenth step on the first flight. Door on the left, two raps, then three." "Thank you, friend," rejoined one of the newcomers, "'tis pleasant to feel that so faithful a watch guards the entrance of this palace of pleasure." Thereupon the two visitors, who of a truth must have been guided either by instinct or by intimate knowledge of the place, for not a gleam of light illumined the entrance hall, groped their way to a flight of stone stairs which led in a steep curve to the upper floors of the house. A rickety banister which gave ominously under the slightest pressure helped to guide the visitors in this utter darkness: but obviously the warning uttered by that mysterious challenging voice below was not superfluous, for having carefully counted sixteen steps in an upward direction, the newcomers came to a halt, and feeling their way forward now with uttermost caution, their feet met a yawning hole, which had soon caused a serious accident to a stranger who had ventured thus far in ignorance of pitfalls. A grim laugh, echoed by a lighter one, showed that the visitors had encountered only what they had expected, and after this brief episode they continued their journey upwards with a firmer sense of security; a smoky oil lamp on the first floor landing guided their footsteps by casting a flickering light on the narrow stairway, whereon slime and filth crept unchecked through the broken crevices between the stones.