"You are mystified--unusual occurrence rather. You can follow the track of a stolen automobile. But when it comes to pursuing an airship, you won't find many familiar roads in the clouds." "How did it happen?" inquired Dave. "Why, we had tested the machine and it was to have been shipped to you yesterday. The day before, our expert made a very fine and satisfactory demonstration. The tanks were full, everything in perfect shape for another spurt early yesterday morning. During the night some one scaled the fence, evaded the watchman, and broke into the aerodrome." "It must have been some one familiar with the place here," suggested Dave. "We don't know that. It is certain, though, that they knew all about airships." "Why so?" "Because from the trail they left we could trace where they ran the machine outside. They gauged its ground run just right. They must have put on the muffler, for the watchman heard no sounds. Then they flew away." "Do you suspect anybody?" questioned Dave. "No." "Could it have been a business rival?" "Scarcely. We have some hard competitors, but we have canvassed the situation and do not believe they could afford to mix up in a deliberate steal." "It is strange," commented Dave, in a musing tone. "Our belief is that the Drifter was selected as the nearest and highest type of aircraft in existence. The people who stole it did so with some definite purpose in view." "What could that purpose be?" asked Dave. "We cannot as yet decide. One thing is certain--they will not venture to use it at any of the aero meets." "Then they must design to take it to a distance." "Of course." "You have no trace of it?" asked Dave. "None whatever. We can account for that, however. The night was dark, they started out when everybody was asleep, and they could have gone in one certain direction and struck a positive wilderness in a few hours time." "You mean north?" "Among the pineries, yes." "Or over the Canadian border?" "Exactly." Dave sat silent and thoughtful for some moments. The situation was a novel one. He had never heard of any one stealing an airship before. The Interstate manager aroused him from his reverie with the words: "We sent for you, Dashaway, because you are our most active man in the field." "That sounds pretty grand for a young fellow like me," returned Dave with a smile, and flushing up, too. "We gage out men by what they do," replied Mr. Randolph in a matter-of-fact tone. "We have found blood the best in our business. You have made good, Dashaway." "Thank you, sir." "Mr. King said you were the most promising aviator in the field." "Oh, he is always saying something good about me." "You proved it in your ideal work with the Baby Racer." "Who wouldn't, with any pride and that perfect machine?" challenged Dave.