"I was just thinking of that," said Mr. Cook. "I certainly would hate to do it." "But he may do some damage." "I know it and I think I know what I'll do. To-night I expect to be at the factory practically all night; I'll keep Heinrich with me on one pretext or another. He'll be right with me all the time so that he won't be able to do any harm and besides I can watch his actions. I am still hoping that he may prove to be loyal." "I'm afraid he won't," said Bob. "I'm afraid not too," agreed his father. "Still I won't let him out of my sight and when morning comes we can decide what ought to be done about Him." "If it isn't too late." "Let's hope not," exclaimed Mr. Cook earnestly. "Hugh and I would like to help guard the factory to-night," said Bob. "I think we have plenty of guards," said Mr. Cook. "You'd better stay home and go to bed; you've had a busy time of it the last two days." "I know it, but we want to help," explained Bob. "Somehow I have a feeling that something is going to happen down there to-night." "Suppose it does, and you get hurt. What would your mother say?" "That's what Karl Hoffmann said," exclaimed Hugh. "Karl is usually right too," said Mr. Cook. "He takes so much responsibility about my personal affairs that really I don't know what I'd do without him." "He was afraid we'd get hurt," sniffed Bob. "Karl likes you," said his father. "He doesn't want anything to happen to you." "We can take care of ourselves." "I know that," his father assented. "Do you want to go very much?" "We certainly do," cried Bob and Hugh in one breath. "Well," said Mr. Cook, "I'm proud of you for wanting to help, and under the circumstances I don't see how I can refuse." "That's great!" cried Bob enthusiastically. "It won't all be fun by a good deal," his father warned him. "We know that, but we're ready to do anything that comes along." The two boys were much excited at the prospect of the guard duty. It seemed to them that at last they had been recognized as capable of aiding in the defense of their country. Perhaps if they had known what awaited them they would not have been quite so enthusiastic. CHAPTER XX ANOTHER SUSPECT Hugh was going home for dinner, and was to return shortly afterward to accompany Bob and his father to the factory. He left the house and Bob started upstairs to prepare himself for the evening meal. On the landing of the stairs he heard some one talking over the telephone and stopped to listen. Of late he had become suspicious of every one and had fallen into the habit of noticing every little thing that happened. It was the cook's voice and he was doubly interested at once. "Yes," he heard her say, "this is Lena." Bob flattened himself against the wall and listened intently. "What's that?" Lena demanded over the 'phone. "In the hospital, you say!" There was a pause while the other person talked to her.