It was evident from the activity in the camp the next morning that something unusual was at hand. At eight o 'clock Ralph burst into the lean-to, which extended out from the hole-in-the-ground shelter, which they called the boudoir, with the startling information that two aeroplanes were hovering about. "What! are they Germans?" asked Alfred, as he leaped up. "No, indeed; one is a Farman, and the other is a Bruegot: I imagine from that there will be some special observation work on hand," answered Ralph, as they moved out of the shadow of the trees, so as to get a good view of them. "Why are they settling down on that side of the hill?" asked Alfred, as an officer appeared. "That is the only available landing place near by," was the answer. "Do they come over frequently?" It was Ralph who spoke. "This is the first time since I have been here," replied the officer. "But we are going to change the range today," he continued, "and we need the flyers to report results." "I am glad of that," replied Alfred. "The commandant is very agreeably surprised at your discovery, and is hoping for good results," he said, as he moved away. "Let's go over to headquarters," said Ralph. "Why not go down and take a look at the machines?" suggested Alfred. "That would be a good idea," responded Ralph, as he led the way. Just then an officer hurriedly marched across the open space behind the guns, and, passing the guard line, moved down the hill to the left. The boys followed. "I suppose that's where he is going," remarked Alfred. The road made a slight turn at a point below the guard line, and one of the machines was just sighted as it passed the brow of the hill and descended the valley. "Hurry up! there it is!" remarked Ralph. "There is the other machine," said Alfred, as he stopped to gaze to the east. A ten minutes' walk brought them close to the plateau, on which the machines had landed. They followed the officer and were soon alongside the Farman. One of the men arose from his seat in the machine, held out his hand toward the boys, and shouted: "What are you doing here?" The boys sprang forward, jumped on the fuselage and extended their hands. "Lieutenant Winston! sure enough!" said Ralph. "No! Captain!" corrected Alfred. "How do you do, Captain?" said Ralph. "I am so glad to see you. You came at the right time." "Well, it seems you always come at the right time, too," replied the captain, as he reached forward with both hands to welcome them. The officer now approached and saluted. "We got our orders this morning to report here for special duty," said the captain. "What is up now? Have the Germans been doing you up?" "Oh, no! Just getting ready to perform that service on them, thanks to the boys," replied the officer, laughing and pointing to them. "Well, that is interesting; if it hadn't been for these boys I would not have had the pleasure of reporting to you this morning," answered the captain.