“Well, then, for another thing, if you check up you’ll find that the spook has appeared every seven days—and this is the seventh night since this last time!”
“Let’s go home, Don,” whispered Chick, across the narrow span of water. Don laughed.
“No, sirree!” he retorted. “In the first place, if it is pure chance, nothing will happen, because it isn’t reasonable that a beam of light from the control room search-lamp would strike a cloud every seventh night and four successive weeks. Besides, it isn’t possible that an airplane would be flying around just at the same time that light came, and that no other ship would be noticed.”
“No,” declared Garry. “My opinion is that it’s some real person who flies out of the clouds, after seeing a ship coming. Then he goes up into another cloud and is lost, and because of the first fib the pilot told to protect himself from censure by the Board of Inquiry sitting about the crack-up, all the rest believe they see a spook.”
“I think he is trying to use the ghost scare to drive business away from Uncle,” Don asserted. “Uncle has several people he can name who are none too fond of him. Any one of them might be doing the ‘spooking.’”
“In that case,” Garry was practical, “if we go up, scouting, that person will know it, and won’t ‘appear’ tonight.”
“That’s why I liked Scott’s plan when he suggested guarding the sky,” Don agreed. “It’s important, too—because Uncle Bruce is expecting to get a big airline to contract for space for its ships, servicing and all that, take-off and landing, and fuel and oil. It will mean a lot to him not to lose that contract. If we prevent any ‘spooking’ tonight, there won’t be any newspaper scarehead stories tomorrow to make the men hesitate about signing up.”
“Then let’s get up out of this stagnant water!” urged Chick, fired by the realistic explanation of the spectre. “We’ll be a sort of Sky Watchman.”
“An Airlane Guard!” suggested Garry.
“That’s it—an Airlane Guard!” Scott agreed. “Well, come in here, Don, take this Dragonfly aloft and cruise around. If you see signs of any other ship than the mail ’plane—it’s due soon—let Garry send over a green flare if it’s in the air, or have Chick fire a red Verey if it goes up off the earth or water—and you go around on wingtip to point to it and start after it, and I’ll come up on a slanting course, and we can corner the fellow, and end the mystery of the Spectre in the Clouds.”