A DOUBLE PUZZLE

Barney stood up and looked at his watch: also, he frowned a little.
“I wish we didn’t have to waste the time,” he objected. “I’ve went
through it all with you, Mr. Wright, and I wanted to take these lads
along back to the plant in my car. I wanted to make it look like I just
happened on them at the accident—the—well, the accident, and found they
were interested in av-iation and brought them back to fill a couple of
places in the plant.”
“But how can we solve a case if we don’t know what it is?” remonstrated
Bob.
To that Curt nodded and Al bobbed his head rapidly.
“As a matter of fact,” Barney turned to Bob, “I think you would do a
whole heap better if you went in to it blind, sort of. If you know all
about it, you’ll go out to the plant, all serious and acting like judges
or detectives. If you take it the way our youngest friend, Al, does—as a
sort of lark—you won’t be suspected so quick.”
“There is something in that,” Mr. Wright admitted. “Al’s face is apt to
give him away if he thinks it is really serious. Perhaps——”
“But all the same, Father,” Bob declared, “how will we know what to
watch for? How will we know what to report?”
“Watch anything you see. Listen to whatever you hear. Report the whole
business!” Barney exclaimed.
“That does seem wise,” Mr. Wright agreed, rising also. “Boys, let’s
emphasize the Sky part of your order, and let the Squad side rest
awhile. Barney wants to get back to the plant—he is the Manager, I meant
to explain. He ought to be at the end of a telephone wire. Let’s say
only this: There is a double mystery. First of all, valuable parts have
been missed, from time to time, from the plant. That is a minor matter,
at present, but your first puzzle is—where have the missing parts gone
and who took them? But, as I said, that is a minor affair, because——”
“Somebody has tampered with some of the finished crates,” broke in
Barney. “Why, and who—that’s the second puzzle!”
“Suppose you take that as enough for the present,” suggested Mr. Wright.
He turned to Barney. “Now these three young lads are alert, obedient,
and they will follow instructions to the letter, if you give orders,” he
explained. “You have already seen how——”
“How quick they are in emergencies! Yes sirree! All right. I know I can
depend on them. Sorry you can’t investigate in person, Mr. Wright—but
maybe this way will work out best. Anyhow, nobody at the plant will get
suspicious of these boys. They won’t have the brains of older men, like
you and me, but they will have quick eyes and wide ears,” he laughed,
and beckoned, “come on, lads.”
A little disappointed, feeling that there was more behind the mystery
than Mr. Wright had disclosed, but accepting his “lead,” Bob, Al and
Curt caught up their caps from the hall rack and followed Barney into
the car.
As he drove toward the large manufacturing buildings, the administration
offices and the assembling rooms, “dope” rooms and testing field that
formed the Tredway Aircraft Corporation plant, Barney kept away from
talk about the mysteries.
Instead, he questioned them about the plan for their new organization,
suggested secret codes, urged them to elect a “Boss Pilot” and really
fired their imaginations to such a point that when they came in sight of
the aircraft plant they had almost forgotten their disappointment at not
being taken fully into his confidence.
“Well,” he said, when they turned in at the gateway in the high board
fence that kept curious wanderers out of the grounds, “here we are, Sky
Squad—ready to begin to learn how a crate is started, what the design
means, and why certain things have to be planned for—and then, what goes
into construction and why, how she’s put together, and then, how to fly
the finished crate.”
Sensing from his tone that he wanted them to concentrate, at least
outwardly, on airplane construction and to let the other part of their
activity be kept quiet, the three comrades agreed by assuming an
interest that was by no means hard to pretend, when he took them into
the offices, introduced them to some of the men working there, and
explained that he was going to put them to work “to learn to build
crates from the prop to the tail skid.” Barney, on the way, had learned
their special interests. Therefore he put Bob into the engine assembling
division where he could learn more about radial engines and the
experiments being conducted with oil-burning types. Curt, who was
methodical, cool and careful, was assigned to work, at least for awhile,
in the wing assembling rooms. Al, being rather young for too much
technical understanding, was assigned as helper to a “rigger,” who had
been grumbling for some time at the laziness of his present assistant.
Everything was so new and so interesting that the trio forgot the
seriousness with which Mr. Wright had assembled them that morning; but
as they rode their bicycles toward home at lunch time, Bob imparted
information that both startled them and turned their minds back to the
serious business really underlying their work.
“I heard some talk, this morning,” Bob told his brother and Curt. “It’s
serious, fellows! Missing parts aren’t half the puzzle—and tampering
with airplanes isn’t all the rest.”
“What is, then?” demanded Al.
“They think, in the wing assembling room,” Curt put in, “that the
airplane fell this morning because something went wrong with Mr.
Tredway. The plant owner was delivering that craft himself. They all
argue that he must have had a heart attack, or something of the sort,
because the airplane was tested and gone over thoroughly. They say he
must have been taken sick and lost control. Is that what you mean?”
“I heard some ‘mechs’ saying they think he deliberately made away with
himself because of money trouble or something they don’t know about,”
added Al. “Maybe trouble with his family, one says.”
“That isn’t it,” Bob said soberly.

“What is?”
“The talk in the engine plant was that some enemy deliberately tampered
with that airplane because—because he knew the owner was to fly it.”
“But—” Curt was astounded, “but, Bob—that would be——”
“Yes,” admitted Bob, very gravely, “yes—it would!”
“That makes the puzzle about missing parts and the rest unimportant,”
Curt commented, thoughtfully.
“But it still gives us two puzzles to solve,” Al began.
“Well,” corrected Curt, “not two separate puzzles—but a double puzzle,
all the same.”
“A double puzzle? I don’t quite see——”
“It’s all one problem,” Bob explained to his younger brother. “But it
has two sections. First—was the airplane tampered with as an act against
the aircraft corporation or against Mr. Tredway in person?”
“And second?——”
Al did not let Curt complete his deduction. Al had one of his own.
“And second—who did it?”