"I'm all ready," she announced. "Where are the other girls?" "In the living room, reading and eating candy--or at least Grace is doing the candy part. Amy has sworn off, you know." The girls agreed eagerly to the proposed swim, and in a few minutes had donned their suits and caps and pronounced themselves ready. "I ought to get a letter from mother to-day," said Mollie, as her feet sank in the soft sand. "She said yesterday that the detectives had picked up a clue and thought they were on the right trail at last." "Why didn't you tell us?" Betty demanded. "Oh, I don't know," Mollie replied wearily. "I didn't think there was any use telling you until I had something really definite. You know the chief business of a detective is nosing out false clues," she finished scornfully. "Well, I know once we met a perfectly capable detective," remarked Betty. By this time they had reached the water and she put one toe into it experimentally. "Ouch--it's cold," she said. "When did we meet a capable detective?" queried Mollie, looking interested. "Just after we went to Camp Liberty when Will traced the German spy," Betty reminded her. "Did you ever see prettier detective work in your life?" "Yes, it was splendid," Mollie admitted, but the reference proved to be an unfortunate one. It brought back vividly the picture of Will as he had been then, at the height of his triumph over the apprehension of the spy--in which the Outdoor Girls had also played an important part--and jubilant at the prospect of being able to join the colors at last and fight in the army of democracy. Try as they would, they could not enter into the fun as they would have done a few weeks before. They swam about languidly and found to their surprise that they became quickly and easily tired. "I never knew before how much influence mind has over matter," said Mollie, after they had come out on the beach again. "I declare, even my muscles feel depressed!" "As Outdoor Girls we're getting to be marvelous failures," remarked Grace, as she wrung the water from her skirt and plumped down in the sand. "I feel as weak as a rag." "I guess it isn't much use trying to enjoy ourselves," sighed Betty plaintively. "I've done my best, but all the time I feel as if I were just trying to kid myself, in the vulgar vernacular." "For goodness sake, don't you give up, Betty!" cried Grace, in alarm. "If you get discouraged, then I don't know what we shall do." "I'm not really discouraged--" Betty began, when a terrified cry cut her short and the girls sprang to their feet bewildered. "Where is it?" cried Mollie, but Betty caught her arm and pointed with shaking fingers to an orange-colored cap bobbing on the water several hundred feet from shore. "It's Amy!" she gasped. "Something must have happened. Come on, girls! Who's going with me?" Without waiting for an answer, she was off like a shot with Mollie and Grace close behind.