It was a bitter struggle that the Aëroplane Scouts were to witness at Soissons, and six days of it had already passed. The earth was still dropping on many graves of the German fallen, and yet, sprawling in attitudes along the heights, in the deep-cut gorges of the plateau, and across the flat valley bed were French infantrymen in their far-to-be-seen red-and-blue uniforms, swarthy-faced Turcos, colonials, Alpine riflemen, and bearded territorials. At staff headquarters, in the first officer that passed near them the boys recognized a familiar figure, no other than Colonel Muller, whom they had first met in far-away Texas, U. S. A., on the day of the record flight, and again in the hangar camp at Hamburg. Billy impulsively stepped forward. "How do you do, Colonel?" The officer instantly turned in his stride to inspect the speaker. "Hello, Boy Aviator," was his hearty greeting. "How under the sun did you ever get here?" "Same old way," said Billy, "the airline, of course." "And here's the other one," the colonel reaching for Henri's shoulder. "By the way," continued the big soldier, "this must be a field day for flyers. Here, Hume, come and see what the wind brought in." The officer addressed moved at quickstep in response to this invitation. It was the aviation lieutenant from Hamburg. He grinned from ear to ear when he laid eyes on his former charges. "Can't lose you if I try," he exclaimed. "Have you enlisted with us?" "No," laughed Billy, "we're still driving cars for the good merchant from your town," with the backward point of the thumb at Roque, who was engaged in close confab with a group of staff members near by. "Did you blow in with Schneider, too?" asked the lieutenant. "I just want to say that you will bore a hole in a stone wall sometime if you train with that fellow. Nature didn't give him red hair without reason." "Now that you are here," broke in the colonel, "you must not be allowed to get out of practice. I expect that one of you will have to give me a ride along the front before long. I have lost three horses this week." "We'll do our best to oblige you, colonel," volunteered Billy. It was no merry jest, that ride Billy gave the colonel! At the time, the French retained a foothold north of the river at only one point--St. Paul--where the bridge from Soissons crosses, and this by a perilous margin, since the bridgehead was completely commanded by German artillery on the heights. The battlefield entire covered a front of about seven miles, the center and eastern flank a high, level plateau rising steeply a couple of hundred feet from the valley of the Aisne. On the western side a deep valley ran northward, bounded on either side by turnpikes. An airman taking the big curve of the river would not be considered a good risk for a well-regulated insurance company. But it could be done--and Billy Barry furnished the proof.