"Doesn't sound likely," the sergeant agreed. "I'd like to know why those two men were enemies though. From all I can learn I should think they were working for the same purpose. Why should that fake detective be so eager to get that paper away from yez, and to get you boys away if he wasn't up to something suspicious?" "Don't ask me," exclaimed Bob. "It's too deep for me, and I get more and more mixed up all the time." "Well, I believe it's just as I said," continued Riley. "They were both parts of the same crowd. There must have been evidence against them in that house and they wanted to destroy it. Your fake detective blew it up and Mr. Wernberg got caught in there by mistake." "How do you explain the locked door?" asked Bob. "I don't, but there must be some explanation for it." "You think it was an accident, don't you?" "I do," said Sergeant Riley firmly. "When Mr. Wernberg gets so he can talk I'll bet he'll say the same thing." Bob merely shrugged his shoulders. He did not think that the sergeant's explanation was correct, but he could offer no better one himself so he said nothing. After all it might be that in the hurry to get away there was a mix up and Mr. Wernberg was left behind, locked in the room. Bob had no doubt in his mind that Mr. Wernberg was a member of a gang that was plotting against the United States. In his heart he felt sure he was guilty. On the other hand if the fake detective was not equally guilty he would be surprised. Certainly no man would disguise himself in that way who had honorable motives. Nor would any man run away as he had done, or fire a pistol at real officers of the law unless he was engaged in some evil doing. How were these two men connected? That was the question that bothered Bob. He felt that there was some connection between them, and yet why should one of them be locked in the second story of a house while the other one put a bomb under it and burned it up? Perhaps after all it was as Sergeant Riley had suggested. "Come on, boys; we'll go home," exclaimed Mr. Cook. "Thank yez for coming with us," said Sergeant Riley, as Mr. Cook and the two boys rose to their feet preparatory to leaving. "Not at all," said Mr. Cook cordially. "If there is anything further we can do to help, please call on us." "I will," said the sergeant. "Thank yez again." "And don't forget to let us know what Mr. Wernberg has to say." "I won't." They went out and got into the automobile and a few moments later were home again. "After you put away the car, I want you to take a note down to the Wernbergs for me," said Mr. Cook to Bob as he mounted the steps of the house. "To tell them what happened to Mr. Wernberg?" "Yes." "I should think it would be better to go and see them." "No doubt it would, but somehow I don't like the idea of having to go and talk to Mrs. Wernberg about it. I suppose I'm a coward."