"They can come in--and go out--whenever they please," answered the elder man. "I tell you we've nothing to do with them--except as their landlords." "Where do you live--yourselves?" asked the Inspector. "On these premises?" "No, we don't," replied the younger brother, who, of the two, had showed the keenest, if most silent, resentment at the police proceedings. "We live--elsewhere. This establishment is opened at eight in the morning, and closed at seven in the evening. We're never here after seven--either of us." "So that you never see anything of these foreigners at night-time?" asked the Inspector. "Don't know what they do, I suppose?" "We never see anything of 'em at any time," said the elder brother. "As you see, this passage and staircase is outside the shop. We know nothing whatever about them beyond what I've told you." "Well--take us up, and we'll see what we can find out," commanded the Inspector. "We're going to examine those rooms, Mr. Pilmansey, so we'll get it done at once." The intervening rooms between the lower and the top floors of the old house appeared to be given up to stores--the open doors revealed casks, cases, barrels, piles of biscuit and confectionery boxes--nothing to conceal there, decided the lynx-eyed men who trooped up the dingy stairs after the grumbling proprietors. But the door on the top floor was closed--and when Ayscough turned its handle he found it to be locked from within. "They've keys of their own for that, too," remarked the younger Pilmansey. "I don't see how you're going to get in, if there's nobody inside." "We're going in there whether there's anybody or not," said the Inspector. "Knock, Ayscough!--knock loudly!" The group of men gathered behind the leaders, and filling the whole of the lobby outside the closed door, waited, expectant and excited, in the silence which followed on Ayscough's loud beating on the upper panel. A couple of minutes went by: the detective knocked again, more insistently. And suddenly, and silently, the door was opened--first, an inch or two, then a little wider, and as Ayscough slipped a stoutly booted foot inside the crack a yellow face, lighted by a pair of narrow-slitted dark eyes, looked out--and immediately vanished. "In with you!" said the Inspector. "Careful, now!" Ayscough pushed the door open and walked in, the rest crowding on his heels. And Purdie, who was one of the foremost to enter, was immediately cognizant of two distinct odours--one, the scent of fragrant tea, the other of a certain heavy, narcotic something which presently overpowered the fragrance of the tea and left an acid and bitter taste. "Opium," he whispered to Lauriston, who was close at his elbow. "Opium! Smell it?"