"Don't you try any of your shooting games, or I'll take a hand in it!"
shouted the detective, and, at the same moment he drew his revolver and
fired harmlessly in the air.

"A bomb! A bomb!", yelled the guards in terror.

"Not yet, but there may be!" murmured Tom. The firing of the shot
produced a good effect, for the three men who were trying to detain Ivan
Petrofsky at once fell back from the window and gave him just the chance
needed. He scrambled through, with the aid of Mr. Damon, and before the
guards could again spring at him, which they did when the echoes of the
shot had died away. They had realized, too late, that it was not a bomb,
and that there was no immediate danger for them.

"Come on!" cried Tom. "Make for the airship! We've got to get the start
of them!"

Leading the way, he sprinted toward the road that led to the place where
the airship awaited them. He was followed by Mr. Damon and the
detective, who had Mr. Petrofsky between them.

"Are you all right?" Tom called back to the exile. "Are you hurt? Can
you run?"

"I'm all right," was the reassuring answer. "Go ahead; But they'll be
right after us."

"Maybe they'll stop when they see this," remarked the detective
significantly, and he held his revolver so that the rays of the