d Ned.

And it seemed to; for, a moment later, an officer and several aides
galloped forward, calling out something in Russian.

"What is it?" asked Tom.

"He says we are under arrest," translated the exile.

"What for?" demanded the young inventor.

Ivan Petrofsky shrugged his shoulders.

"It is of little use to ask--now," he answered. "It may be we have
violated some local law, and can pay a fine and go, or we may be taken
for just what we are, or foreign spies, which we are not. It is best to
keep quiet, and go with them."

"Go where?" cried Tom.

"To prison, I suppose," answered the exile. "Keep quiet, and leave it
to me. I will do all I can. I don't believe they will recognize me.

"Bless my search warrant!" cried Mr. Damon. "In a Russian prison! That
is terrible!"

A few minutes later, expostulations having been useless, our friends
were led away between guards who carried ugly looking rifles, and who
looked more ugly and menacing themselves. Then the doors of the Russian
prison of Owbinsk closed on Tom and his friends, while their airship
was left at the mercy of their enemies.

CHAPTER XIX

LOST IN A SALT MINE

The blow had descended so suddenly that it was paralyzing. Tom and his
friends did not know what to do, but they saw the wisdom of the course
of leaving everything to Ivan Petrofsky. He was a Russian, and he knew
the Russian police ways--to his sorrow.

"I'm not afraid," said Tom, when they had been locked in a large prison
room, evidently set apart for the use of political, rather than
criminal, offenders. "We're United States citizens, and once our
counsel hears of this--as he will--there'll be some merry doings in
Oskwaski, or whatever they call this place. But I am worried about what
they may do to the Falcon."

"Have no fears on that score," said the Russian exile. "They know the
value of a good airship, and they won't destroy her."

"What will they do then?" asked Tom.

"Keep her for their own use, perhaps."

"Never!" cried Tom. "I'll destroy her first!"

"If you get the chance!" interposed the exile.

"But we're American citizens!" cried Tom, "and--"

"You forget that I am not," interrupted Mr. Petrofsky. "I can't claim
the protection of your flag, and that is why I wish to remain unknown.
We must act quietly. The more trouble we make, the more important they
will know us to be. If we hope to accomplish anything we must act
cautiously."

"But my airship!" cried