Then they told the story of their search, and the unexpected clew from Russia. In turn the exile told how he had been attacked at the breakfast table one morning by the three spies—the very men who had been shadowing him—and taken away secretly, being drugged to prevent his calling for help. He had been kept a close prisoner in the lonely hut, and each day he had expected to be taken back to serve out his sentence in Siberia.
"Another day would have been too late," he told Tom, when he had thanked the young inventor over and over again, "for the papers would have arrived, and the last obstacle to taking me back to Russia would have been removed. They dared not take me out of the United States without official documents, and they would have been forged ones, for they intended trumping up a criminal charge against me, the political one not being strong enough to allow them to extradite me."
"Well I'm glad we got you," said Tom heartily. "We will soon be ready to start for Siberia."
"In this kind of a craft?"
"Yes, only much larger. You'll like it. I only hope my air glider works."
By putting on speed, Tom was able to reach Shopton before midnight, and there was quite an informal celebration in the Swift homestead over the rescue of the exile. The detective, for whom there was no further need, was paid off, and Mr. Petrofsky was made a member of the household.
"You'd better stay here until we are ready to start," Tom said, "and then we can keep an eye on you. We need you to show us as nearly as possible where the platinum field is."
"All right," agreed the Russian with a laugh. "I'm sure I'll do all I can for you, and you are certainly treating me very nicely after what I suffered from my captors."
Tom resumed work on his air glider the next day, and he had an additional helper, for Mr. Petrofsky proved to be a good mechanic.
In brief, the air glider was like an aeroplane save that it had no motor. It was raised by a strong wind blowing against transverse planes, and once aloft was held there by the force of the air currents, just like a box kite is kept up. To make it progress either with or against the wind, there were horizontal and vertical rudders, and sliding weights, by which the equilibrium could be shifted so as to raise or lower it. While it could not exactly move directly against the wind it could progress in a direction contrary to which the gale was blowing, somewhat as a sailing ship "tacks."