"And now I will tell you the secret which I hold, and which at present is known only to two other men," said the Rittmeister, and, sitting down about the gnarled roots of an upturned tree, the two airmen listened to the following story: "You have heard me sometimes speak of a great mathematician and engineer, by name one Professor Weissmann," began von Spitzer. "Yes, we have heard of him," replied the others. "He is the greatest living scientist; moreover, he is a practical engineer, and during the last four years he has devoted his time entirely to designing, constructing and perfecting with his own hands, assisted by one other mechanic, a wonderful aeroplane, compared to which neither the Allies nor the Central Powers have anything to approximate." "Donnerwetter, but why wasn’t it ready before?" exclaimed Max. "It might have turned the tide of battle in the autumn of 1918." "It’s no use crying over spilt milk," replied the chief. "It could not be completed before." "And you say that this wonderful machine is now ready," interposed Max, who had flown every type of machine from a single-seater scout to a heavy bomber, and whose professional curiosity had now been thoroughly awakened by the words of the German ace. "It is ready, and what is more to the point, it is at my disposal," returned the chief briefly. "Der Teufel! But where is it?" "I can lead you to it, for it is less than three miles from where we sit at the present moment." "Himmel!" exclaimed both the pilots, springing to their feet. "Take us to see it, Rittmeister; we have given you our promise." "Be calm, my friends; you shall see it to-day. But let me put you on your guard. You must not speak of it aloud, but only in whispers, for the secret of this machine is jealously guarded, and its whereabouts is unknown, save to the professor, his assistant and myself." "Has it ever been flown?" ventured Max. "Yes." "Who was the pilot?" "I was." "You, Rittmeister?" exclaimed the amazed airmen. "Yes." "And you are satisfied at her performances?" asked Carl, gazing steadfastly into the eyes of his chief. "More than satisfied. She is the most wonderful and responsive thing I have ever flown. You will say the same when you have seen her, and made a trip or two." "Phew! take us to see her now; I would give ten years of my life to fly in her," said Max, who was getting almost feverish in his anxiety to see this wonderful thing and to handle her controls; for such is the lure of the air, especially to those who have climbed into the azure and sailed amongst the clouds in the days of their youth. "You shall fly in her," replied Spitzer. "When?" asked the eager youth. "When we start our great adventure," replied the chief. "And when will that be?" "To-morrow, if you are willing; all our plans are laid." "Why to-morrow?" asked the others simultaneously.