The next moment Sergeant Falkner was at the low window, which he threw open, and stepped out upon the balcony, but in an instant he came back-- very hastily back--into the room, and hurried to the door, which he opened, to take the key from the outside and carefully lock it from within--the key being afterwards placed in his pocket. A few seconds more, and, to the surprise of Sir Francis and Clayton, he was again in the balcony, where he uttered a low cough. There was a pause of a few moments, when he stooped over, and leaning down, spoke to some one beneath. Apparently satisfied, he re-entered the room, closed the window, unlocked the door, and began to walk up and down thoughtfully, tapping his teeth the while with the end of his pencil. "For what are we waiting, sergeant?" said Sir Francis, anxiously. "Cab, sir," said the officer, curtly; "and here it is. After you, gentlemen!" As he spoke, there was the sound of wheels grating against the kerb below; and a few minutes after the party was rattling through the streets, but only to stop before long at a quiet-looking office. Springing out, the sergeant signed to a policeman, who seemed to be there by accident, but all the same was ready to take his place by the cab-door, adding nothing to the ease and comfort of Mr John Screwby, who was quite as fidgety when, after a few minutes, the sergeant returned, gave a few instructions to the driver, and they were once more rattling through the gas-lit streets. "Rather a tight fit, gentlemen," said the sergeant, "four in one of these cabs; but it won't be for long." In effect, sooner than Clayton anticipated, the cab stopped and the sergeant again sprang out. "Now, gentlemen," he said, "perhaps you'll have the goodness to follow at a little distance. It's two streets off yet; but in this extremely pleasant and salubrious region, we don't want to make any fuss. My dear friend Mr John Screwby and I will go on together, so as to show the way. You need not be afraid," he whispered to Clayton. "Keep tight hold of the old gentleman's arm, and bring him along quickly. There's plenty of help close at hand." Clayton nodded, and then, as he drew the baronet's arm through his own, he hastily glanced round to see once more the thronging types of misery and vice that he had encountered on his previous visits: there were the same hulking ruffians, short of hair, sallow of face, and low of brow-- own brothers in aspect of the gentleman who had turned informer; there, too, were the same slatternly women, old and young; children who never seemed to have been young; and at nearly every corner the gin-palace in full levee, its courtiers thronging in and out as the doors swung to and fro.