"So these are your friends?" he said, quietly, as the boys gathered about him, with faces expressive of anything but welcome. "I rather thought I should tumble on something like this. Introduce me, Frank. It will take off the awkwardness a bit." "Oh, we don't want to know you, boss," spoke up one of the boys, with a threatening air. "We don't allow no visitors, we don't, and we're going to show yer, too, blame quick." "Yes," growled Garibaldi, the Italian boy, "disa whata coma from taka in de stranger among us." As for Jerry Buck, Barney the bootblack, and Frank himself, they stared at one another, the two Bats surveying the boy whom they had befriended with angry looks, Frank regarding them with a face upon which was seen plainly imprinted every evidence of innocent surprise. He did not dare to offend the detective, who could, as he was well aware, throw him into the hands of the law at any moment. He felt both sorry and ashamed to think that the kind-hearted boys who had befriended him in his trouble should for a moment think that he had betrayed their hiding-place to a member of the police. "Is this feller a friend of yourn?" demanded Barney, in no pleasant tone. "It is Detective Hook, boys," replied Frank, with as much firmness as he could muster. "I swear to you all that I never breathed a word." "I knowed it," muttered Jerry beneath his breath. But Caleb Hook, with a keen realization of the way matters stood, gave no opportunity for further words. He had suspected the existence of just such a place as this from the first moment of Frank's mysterious disappearance on the previous night. Now, it was a life rule of this remarkable man that no suspicion worthy of entertaining at all should be abandoned until either its truth or its falsity had been proved. It was for that reason he had chosen for his meeting with this boy, in whose strange case he was becoming hourly more interested, the time and place he had. "Hold on, boys," he said, a broad smile breaking over his face, "before you fire me out of here, before that little Italian sticks a tooth-pick into me or you condemn Frank Mansfield for a traitor, hear what the detective has got to say." "Well, say on, den, blame quick!" exclaimed Sandy the Bat, who had first spoken, "for we fellers is a-goin' to pound the life outer yer in jest about a minit and a half." "Indeed! Well, I'm not afraid. In the first place I swear now, without being asked, never to give this place away, provided I catch none of you boys transgressing the law. Second, I tell you now, and tell you the truth when I say it, that this young man, Frank Mansfield, never by so much as a word told me anything about this place, any boy here present, or gave me the slightest clew how to enter it as I did." All the boys stared at the detective in surprise. "I knowed it," growled Jerry Buck again. "How could Frank Mansfield tell him about the up-stairs way, fellers, when he didn't know nothing about it himself?"