own on his face. "It's puzzled me a whole
lot, let me tell you, Andy. Because, of course, my first thought was
that it must have been Percy Carberry's work; but now that you tell me
he was here, and knew we hadn't fetched our hydroplane home, I hardly
know what to think."

"Did you say you worked till about eleven at the shop?" asked Andy,
quickly.

"Three minutes after when I quit, locked up, and went home," Frank
replied.

"That was just about the time they showed up here," the other went on to
say. "Unless one of us is wrong about the time, they couldn't well be in
two places at the same minute, now, could they? Seems like it might have
been some other crowd that broke into our hangar, Frank!"

"But why? Did they want to play fast and loose with our machine, and
force an entrance just for that purpose? Listen to something I'm going
to tell you, Andy. I found several things on our work bench where
somebody had left them, without meaning to do it, I guess. Here's one."

Frank while saying this held something up which he had taken from the
package he carried under his arm.

"Why, that's a splendid electric torch, looks like to me?" exclaimed
Andy.

"Just what it is, now," the other agreed.

"And it was forgotten in our shop, was it?" demanded Andy.

"I made out that whoever entered used this first, and then lighted our
lamp to look around with, putting out the torch, and laying it down.
When they skipped out, why, they just forgot all about it, also these."

Again did Frank make a dive into his pocket, and dangled something
before the astonished eyes of his cousin.

"Great Caesar! what d'ye call those things?" gasped Andy, staring as
though hardly able to believe his eyes.

"Well, as near as I can make out, they're a couple of half masks made
out of black muslin, and just like a domino worn at a masquerade ball."
Frank remarked, with positive conviction in his voice and manner.

"Masks?" echoed the other; "and the fellows who broke open our shop wore
them, did they? Well, the crowd that came out here seemed to be
satisfied to tie handkerchiefs across their faces, and pull their hats
down."

"I don't know that they wore them," Frank went on, "but they had the
things along and laid them down with the lantern, forgetting the whole
lot when they cleared out. Perhaps your dog got to barking and
frightened them off before they found a chance to do much damage."

"A regular bullseye electric torch, and black