steriously.

"Just a couple of seconds sooner and we'd have seen who brought
her here," went on Tom. "But they must have shut off the motor
some distance up, and then they volplaned down. That's why we
didn't hear them."

Ned went over and put his hand on the motor.

"Ouch!" he cried, jumping back. "It's hot!"

"Showing that she's been running up to within a few minutes ago,"
said Tom. "Well, as I said before, this sure does get me. First
these mysterious men take my airship, and then they bring her back
again, without so much as thanking me for the use of her."

"Who in the world can they be?" asked Ned.

"I haven't the least idea. But I'm going to find out, if it's at
all possible. We'll look the machine over in the morning, and see
if we can get any clues. No use in doing that now. Come on, we'll
put her back in the hangar."

"Say!" exclaimed Ned, as a sudden idea came to him. "It couldn't
be Mr. Damon who had your airship; could it, Tom?"

"I don't know. Why do you ask that?"

"Well, he might have wanted to get away from his enemies for a
while, and he might have taken your Eagle, and--"

"Mr. Damon wouldn't trail along with a crowd like the one that
took away my airship," said Tom, decidedly. "You've got another
guess coming, Ned. Mr. Damon had nothing to do with this."

"And yet the night he disappeared an airship was heard near his
house."

"That's so. Well, I give up. This is sure a mystery. We'll have a
look at it in the morning. One thing I'll do, though, I'll
telephone over to Mr. Damon's house and see if his wife has heard
any news. I've been doing that quite often of late, so she won't
think anything of it. In that way we can find out if he had
anything to do with my airship. But let's run her into the shed
first."

This was done, and Koku, the giant, was sent to sleep in the
hangar to guard against another theft. But it was not likely that
the mysterious men, once having brought the airship back, would
come for it again.

Tom called up Mrs. Damon on the telephone, but there was no news
of the missing man. He expressed his sympathy, and said he would
come and see her soon. He told Mrs. Damon not to get discouraged,
adding that he, and others, were doing all that was possible. But,
in spite of this, Mrs. Damon, naturally, did worry.

The next morning the two chums inspected the airship, so
mysteriously returned to them. Part after part they went over, and
found nothing wrong. The motor