We changed places, and I started off at a speed of about ten miles an hour. The doctor lifted a small portable radio set from behind the back seat, adjusted the tuning dials, and slowly moved the loop aerial back and forth until there was an angry buzz from inside the machine. He then continued to slowly turn the loop aerial as we moved along, apparently with the purpose of keeping it in a position where the machine would buzz the loudest. I noticed that, at first, the direction of the loop only made a very slight deviation from the direction in which we were going. Gradually, however, the deviation grew greater until the loop stood at right angles to our course. We were, at the moment, passing the entrance to a lane, which led to a farmhouse set back about half a mile from the road. As we continued past the lane the aerial gradually straightened out toward our course. About a thousand feet beyond the entrance to the lane was a brightly-lighted filling station. We stopped there, left the car in charge of the service man, and started across the fields. When we had gone a short distance, the doctor handed me an automatic pistol. “I hope we won’t have to do any shooting,” he said, “but it’s safer to be prepared.” It took us all of ten minutes to reach the farmhouse. It was in darkness, except for one of the rear rooms, which was dimly lighted. Admonishing us to tread carefully, the doctor led the way around the house. As we rounded the rear porch, I saw that a four-wire aerial had been stretched between the gable of the house and the barn. A wire connected to the aerial led down into the dimly lighted rear room. Instructing us to stay where we were, the doctor crept stealthily up on the porch and peered through the window. For five minutes at least he stood there, looking into that room while we waited below. Then he turned and beckoned to us. Neither Hogan nor I lost any time in getting up to the window. I’m sure he was as curious as I to learn what was going on in that room. Seated on a long bench before an instrument board which contained a bewildering array of dials, buttons and levers, was a short, bull-necked man. He wore a close-cropped, bristling pompadour, a thin, fiercely upturned moustache, and an immense pair of thick-lensed, horn-rimmed spectacles. A set of headphones covered his ears, and his pudgy hands worked incessantly with the levers, dials and buttons on the board before him. The only light in the room came from a panel of frosted glass which was just above the instrument board. On the panel, which the operator constantly watched, was a very clear shadow picture of the living room I had quitted only a short time before, in the home of Miss Van Loan.