Bob, looking in, saw a heavy man, a huge thatch of hair bristling over his forehead, at a flat-topped desk. He rose as they entered. “Hello, Hughes,” greeted the major. “Right on time.” He nodded toward a desk clock. “Made it with nothing to spare,” grinned Bob’s uncle. Then he added, “Major, I want you to know my nephew, Bob Houston. He’s working with me on this case. Bob’s the man who captured our radio thief last night and I’m counting on him as a valuable inside man in the department over there.” “Glad to meet you,” boomed the major, offering a warm handclasp. “Are you in the Department of Justice?” Bob started to reply but his uncle spoke first. “He’s in the filing division right now, but he’s also a provisional agent and I’m expecting he’ll join the service permanently.” The major shuffled several papers on his desk and picked up one. “Here’s a copy of the paper stolen last night,” he said. “I know you want the gist of its importance and why so much interest attaches to it.” He waved them toward chairs and dropped back in his own swivel seat, which he filled to overflowing with his generous bulk. “We’ve been making some real strides in our army radio development,” he went on, “and some other powers have been watching us closely. There’s no need to mention names right now until suspicion definitely points to a nation. What we have actually perfected in recent weeks is a workable radio control for robot operated bombing planes.” He paused a moment to let the significance of his statement sink in. Bob knew its importance. Of course there had long been talk that such a device was possible, but it had never been perfected so far as he knew. Its value as a weapon of destruction was tremendous for airplanes loaded with high explosives could be dispatched over great distances and then made to drop their deadly cargoes upon a radio signal. Bob glanced at his uncle. Merritt Hughes was sitting on the edge of his chair, waiting for the army officer to continue. Major McCreary cleared his throat and Bob sensed that he was laboring under a definite strain. “This project has been a pet of mine for years. I’ve encountered one discouragement after another and it was only two months ago that I struck the right track. Since then my developments have been almost sensational.” He paused a moment as though fearing they might feel he was bragging about his own accomplishments. “Actual tests last week proved the practicability of my invention and I then set it down in detail for final filing. Of course we knew that other powers were aware of the line along which the experiments had been carried out, but our real source of worry was that they might get their hands on the actual details of operation. For that reason it was decided to file the material in various sections and to make no special fuss about it.” “And the paper stolen last night was the first section of your file?” asked Merritt Hughes, restraining his eagerness no longer.