"And if we find out that they are really his sons, what then?" queried Grace, and this time Betty looked puzzled and Mollie and Amy completely beyond their depth. "Why then," said Betty hesitatingly, "I'm sure I don't just know what we ought to do. But don't you think," she added, brightening, "that it might be a good idea to wait until we have found out definite facts before we try to solve any more problems?" Rather reluctantly the girls agreed and, after making Betty promise that she would let them know the very first minute she found out the names of Arnold Dempsey's sons, they said good-bye and started for home. Of course Betty had already told her father and mother about Professor Dempsey and the part he had played in actually saving their lives; so when she told them that night of what she had read in the paper and begged her father to help her find out whether the dead soldiers were really Arnold Dempsey's sons or not, he readily consented to do what he could. "I'll drop in and see Haig to-morrow," he promised. "I have often heard him speak of Professor Dempsey as being one of the best professors of zoölogy up at the university and I am sure I will be able to find out what you want to know. I hope you have been mistaken in your conclusions, for it would be a horrible blow to a man to lose both his grown sons at once and like that. Now run off to bed and tomorrow I may have some news for you." With this Betty was forced to be content. She went to bed of course, there was nothing else to do, but she tossed restlessly all night and what sleep she got was checkered with horrid dreams and she woke up in the morning feeling as though she had not been to sleep at all. The next day was a long one to live through, even though the girls did keep calling her up at frequent intervals to see if she had any news for them yet. She became so tired of hearing the telephone bell ring at last that she stuffed a handkerchief between the bell and the clapper and sat down to read a novel and while away the time as best she could till her father came home. Luckily for her--and him too, perhaps--Mr. Nelson did get home early, and he was no sooner inside the door than Betty grabbed him by the arm, led him over to a divan in the corner of the living room, and let loose upon him a flood of questions. "Did you see him? What did he say? Why didn't you let me know sooner?" These and various other queries were hurled at Mr. Nelson so fast that it is no wonder the poor gentleman appeared slightly bewildered. But knowing his impetuous young daughter of old, he merely pinched her cheek fondly and waited for her to give him a chance to speak. "If you will wait just a moment I will try to tell you about it," he said at last, mildly. "There's only one thing I really want to know, Dad," said Betty soberly. "And that is the name of Professor Dempsey's sons." Her father shook his head slowly, regretfully.