"Guess we'll have to get some regular detectives on it," suggested Ned.
"And that's what I'll do," declared the young inventor. "They may be able to locate Mr. Petrofsky before those spies take him out of this country. If they don't—it will be too late. I'm going to talk to dad about it, and if he agrees I'll hire the best private detectives."
Mr. Swift gave his consent when Tom had told the story, and, a day later, one of the best detectives of a well known agency called on Tom in Shopton and assumed charge of the case.
The early reports from the detective were quite reassuring. He got on the trail of the men who had taken Mr. Petrofsky away, and confirmed the suspicion that they were agents of the Russian police. He trailed them as far as New York, and there the clews came to an end.
"Whether they are in the big city, which might easily be, or in some of the nearby towns, will take some time to learn," the detective wrote, and Tom wired back telling him to keep on searching.
But, as several weeks went by, and no word came, even Tom began to give up hope, though he did not stop work on the air glider, which was nearing completion. And then, most unexpectedly; a clew came—a clew from far-off Russia.
