THE DETECTIVE’S THEORY

More startling than Bob’s fresh information was the revelation given by
Barney, the information which had brought him, flying, to consult the
detective he had engaged to solve the puzzling case.

All that Bob had to tell was the suspicious act of the youth, Griff.

Barney, because it was so late, gave only a hint; but what he said
caused a great deal of sleeplessness on Bob’s part, at least.

“We got the wrecked airplane up,” Barney told them all, that night.
“I’ve had it hauled in and dismantled.”

He paused to give his next words more emphasis.

“There wasn’t one thing wrong with that crate!”

When, during their Sunday morning conference, he amplified his
statements, the mystery deepened.

Dismantled, thoroughly examined, by Barney, in person—he did not trust
any subordinate in so important a matter—the airplane revealed nothing
wrong, either with its engine, with its wings, or with its controls!

“But it fell,” commented the detective. “What, do you imagine, caused
the crash?”

“I give it up.” Barney was unable to make a theory. “I hired you to do
the doping out of that! I give you the facts. You do the rest.”

“Bob,” his father turned to the youth, “have you jotted down all the
suspicious things you mentioned, as I asked you to do?”

Bob nodded and handed over a paper.

After consulting it and comparing it with a sheet on which he had
written, Mr. Wright looked up.

“This is what we know,” he began. “For several months, according to
Barney’s original explanation, when he gave me the case, airplane parts
had been missed. Not very many, but some. We have to decide how they are
taken, and then find out who does it and what happens to them, how they
are disposed of.”

“How about the man who gives out the instruments and such?” asked
Langley quickly. Bob thought he said it to forestall comment about
Griff, “or the mechanics whom Al had been told by his rigger boss were
possible culprits?”

“We haven’t been able to watch everybody,” Bob said.

“That point is not important,” Mr. Wright declared. “It is the beginning
of what we know, and can wait. Our second bit of knowledge—and more
important this is, too—is that for several months before the seemingly
fatal crash, accidents had occurred to every airplane that was sent out
of the plant. Buyers complained by letter, and only by good luck was it
possible to avert several tragedies.”

“I didn’t know it had been as bad as that,” Bob commented.

“It had,” Barney nodded. “We wanted you three boys to start in with open
minds. Remember? We didn’t tell you details; but now it’s gone too far
for taking things easy. We’ve got to get to work.”

“Right,” agreed the detective. “The third point we know is that Mr.
Tredway was very anxious to hold up the good name of his corporation,
and that he decided to take this last ship to its owner in person, after
Lang, here, gave it—” he paused, noticing Bob’s expression.

“I know what’s on your mind,” Langley said, turning to his younger
cousin. “I was the one who tested and checked that Silver Flash. I said
she was O.K. before the take-off. But,” his manner was defensive, “if
you think——”

“I don’t think,” Bob asserted. “For a minute I did—but Mr.—but Barney
says not a thing was wrong about the Silver Flash. So, of course,
there’s nothing to think.”

“Besides,” said Barney, “we none of us knew it would be the Silver
Flash. The buyer couldn’t make up his mind, till almost the last minute,
about that pair of twins. One time he’d come and say he liked the
silver, then he wanted the copper-gold finish. Both crates were
identical except for that. I thought, myself, he was going to take—well,
we all thought the last time he came he wanted the gold one. But I guess
he telegraphed.”

“Well, then, that explains one thing,” said Bob. “If everybody thought
he wanted the Golden Dart, that’s why the rudder rope was frayed off in
that ship.” Barney, who had been told everything, nodded.

“Yes,” he admitted, “but that don’t explain why the other ship—sound and
perfect—crashed. Unless——”

“Unless—what?” Bob, Lang and the detective were interested, but Bob
voiced the question.

“Unless Mr. Tredway did it on purpose—crashed!”

“Why should he?”

To Mr. Wright’s quiet inquiry Barney answered readily enough.

“I run the plant,” he said. “The deep part of the money end, and all
that is none of my business. But I happen to know there’s some trouble
about money, or losses, or something like that.”

“You think—” Mr. Wright bent forward, “—Tredway, because he was in some
financial difficulty, or deeper trouble, might have done away with
himself?”

“Well,” defensively Barney replied, “how else do you account for a
diving ship, placed so careful, on the lakeside, close to shore, and
only damaged as little as possible, and then not from anything being
wrong in her?”

Bob saw that his father was very thoughtful.

“Do you think he ran off and hid, afterward?” he demanded.

“They didn’t find hide nor hair of him, did they? Dredging, or searching
didn’t locate anything!”

“That’s so!”

“However,” the detective objected, “that doesn’t explain about the
frayed cable, or the other things done to airplanes to damage the
reputation of the corporation; that is my theory about the motive.”

“No,” Barney admitted. “If you’ve got a theory about the motive for
damage to crates, maybe you’ve got one about the whole affair.”

“I have.”

“What is it, Father?” Bob was eager to hear.

“There are three crimes to investigate,” Mr. Wright said slowly. “The
accidents, the thefts, and the——”

“Do you still think Mr. Tredway’s disappearance was due to a crime?”

“Yes, Lang, I do.”

“What sort of crime? Nothing is wrong with the ship he used, Barney
says,” objected Bob.

“A very strange one,” his father replied. “Remember—there was a brown
airplane hidden in a field. It was gone—before the accident. My theory
is that either some one he feared, or some one who hated him, took off
in that brown airplane, overtook or waited for Mr. Tredway—and——”

“Rode him down!” gasped Barney. “I’d thought of that!”

“Yes,” agreed the detective, “let’s drop all worry about the less
important thefts, the deliberate damage to the airplanes—and look for
the man who flew that brown airplane!”

“Will we?”

Bob asked it as a question, then he repeated it as an exclamation.

“Will we!”