get his aeroplane in shape for the trip back to Shopton.

CHAPTER III

THE HAND OF THE CZAR

"Then you won't take a ride with me to-day?" asked the young inventor,
of the Russian, as he completed the repairs to the magneto. "I'd like
to have you meet my father, and a friend of his, Mr. Damon. Most likely
he'll go to Siberia with us, if his wife will let him. I'd like to talk
some plans over with you."

"I shall certainly call on you," answered Ivan Petrofsky, "but," he
added with a smile, "I think I should prefer to take my first ride in
your larger airship--the one that doesn't come down so often."

"Well, perhaps it is a little easier on an amateur," admitted Tom. "If
you'll come over to our house at any time I'll take you out in it, or
I'll call for you."

"I'll come over in a few days," answered the escaped exile. "Then I'll
tell you all I know of the locality where the platinum mine is located,
and we can make our plans. In the meanwhile don't say anything about
what I have told you."

"Why?" asked Ned quickly.

Mr. Petrofsky approached closer to the lads, and in a low voice said:

"I am not sure about it, but of late I think I have been shadowed. I
have seen strange men in the village near here and they have eyed me
rather suspiciously. Then, too, I have surprised several men around my
house. I live here all alone, you know, and do most of my own work, a
woman coming in occasionally to clean. But I don't like these
suspicious characters hanging about.

"Who do you think they are?" asked Tom

"I'm almost afraid to think, but from my past experience I think--nay,
I fear--they may be spies, or agents of the Russian government."

"Spies!" cried Ned.

"Hush. Not so loud," cautioned Mr. Petrofsky. "They may even now be in
hiding, especially since your aeroplane landed so near my house. They
may see something suspicious even in that."

"But why should the Russian government set spies on you?" asked Tom in
a low voice.

"For two reasons. I am an escaped exile, and I am not a citizen of the
United States. Therefore I may be sent back to the sulphur mines. And
another reason is that they may think I know the secret of the platinum
treasure--the lost mine."

"Say this is getting interesting!" exclaimed Tom. "If we are going to
have a brush with some of the spies of the Russian government so much
the better. I'm ready for 'em!"

"So am I!" added Ned.

"You don't know them," said Mr. Petrofsky,