he attack must have started in the
engine-room," he went on, with a look at Mound and Ventor. "What
happened there?" he asked.

"Well, that's about the way it was," answered the engineer. "We were
working away, making some adjustments, oiling the parts and seeing that
everything was running smoothly, when, all at once, I heard Koku yell.
He had gone in the oil room. At first I thought something had gone
wrong with the ship, but, when I looked at the giant, I saw he was
being attacked by four strange men. And, before I, or any of the other
men, could do anything, they all swarmed down on us.

"There must have been a dozen of them, and they simply overwhelmed us.
One of them hit Koku on the head with an iron bar, and that took all
the fight out of the giant, or the story might have been a different
one. As it was, we were overpowered, and that's all I know until we
were carried in here, and saw you folks all tied up as we were."

"They burst in on us in the same way," Tom explained. "But where did
they come from? Where were they hiding?"

"In the oil and gasoline storeroom that opens out of the motor
compartment," answered Mound, the engineer. "It isn't half full, you
know, and there's room for more than a dozen men in it. They must have
gone in some time last night, when the airship was in the hangar, and
remained hidden among the boxes and barrels until they got ready to
come out and overpower us."

"That's it," decided Tom. "But I don't understand how they got in. The
hangar was well guarded all night."

"Some of your men might have been bribed," suggested Ned.

"Yes, that is so," admitted Tom, and, later, he learned that such had
been the case. The foreign spies, for such they were, had managed to
corrupt one of Tom's trusted employees, who had looked the other way
when La Foy and his fellow-conspirators sneaked into the airship shed
and secreted themselves.

"Well, discussing how they got on board isn't going to do us any good
now," Tom remarked ruefully. "The question is--what are we going to do?"

"Bless my fountain pen!" cried Mr. Damon. "There's only one thing to
do!"

"What is that?" asked Ned.

"Why, get out of here, call a policeman, and have these scoundrels
arrested. I'll prosecute them! I'll have my lawyer on hand to see that
they get the longest terms the statutes call for! Bless my pocketbook,
but I will!" and Mr. Damon waxed quite indignant.

"That's easier said than done," observed Torn