"Yes, unfortunately." "Couldn't the guard see what he looked like?" "Yes, he did see that, and here is the interesting part." "What do you mean?" "Why," said Mr. Cook, "the man was rather slight, weighing perhaps a hundred and fifty pounds and he had a close-cropped black mustache." "The fake detective!" exclaimed Bob. "Was that who it was?" "The description fits him, doesn't it?" "Yes," agreed Hugh, "but he was out at the old house this afternoon. How could he be on the river at the same time?" "He was out at the old house early this afternoon," said Mr. Cook. "This episode at the bridge happened only about an hour ago." "He must have hurried right down there," exclaimed Bob. "When he realized that the police were on his trail he probably decided he had no time to lose, and that's why he dared try such a thing in broad daylight." "Where did you hear about it, Mr. Cook?" inquired Hugh. "Sergeant Riley just told me over the telephone; I had called him up to inquire how Mr. Wernberg was getting along." "How is he?" asked Bob. "Pretty bad yet; once in a while he recovers consciousness, but only for a few minutes. Besides he suffers so from his burns he can't do any talking." "And meanwhile his gang keeps on working," said Hugh. "Is that fake detective part of his gang?" said Bob. "He's the one who blew him up." "I don't know," exclaimed Hugh in despair. "We just go 'round and 'round in circles and don't seem to get anywhere at all." "But the fact remains, doesn't it, boys," inquired Mr. Cook, "that whether we know who the gang is, and what the relations are between the two gangs--if there are two--that somebody is hard at work plotting against this country? Also they are becoming bolder for they know that their time is short; sooner or later they are bound to be caught." "You're afraid for your factory to-night, aren't you, father?" asked Bob. "I am, indeed," said Mr. Cook. Bob was on the point of asking if he and Hugh might not help guard it when the telephone rang and his father was called away to answer it. CHAPTER XVIII KARL HOFFMANN "Let's go down and talk to Heinrich," exclaimed Bob when his father left the room. "Aren't you going to ask your father if we can stand guard to-night?" "Wait till after dinner. I'll ask him then." "Do you think he'll let us?" "I guess so. It depends on how badly he needs us." They went out, and just at the corner of the porch met Karl Hoffmann. He had said good-by to Lena and was on his way home. Bob knew him well, as he did most of his father's employees, for much of his spare time was spent down at the factory. Furthermore, on account of Lena, Hoffmann was a frequent visitor in the Cook home.