Gatton looked at me, smiling in grim triumph; and:
"Dr. Damar Greefe has a residence somewhere within a quarter-mile radius of this house!" he declared. "He has betrayed himself! Then—look here."
Unscrewing the front of the mouthpiece of the false telephone, he took out the strip of cardboard upon which my number was written, turned it over ... and there upon the back was another number!
"Just look up Dr. Brown-Edwards," he said. "He was the last occupant of the Red House, and may still be in the book."
Grasping the purpose of his inquiry, excitedly I did as he directed; and there sure enough the number appeared!
"The identical instrument that was used at the Red House!" cried Gatton. "Note the artistic finish with which even the correct exchange numbers are looked up!"
I sank back in my chair, silent, appalled at the perverted genius of this fiend whom we were pitted against in a life-or-death struggle. But presently:
"What was the object of the opening and closing of the garage doors at the Red House?" I asked, almost mechanically.
"Simple enough," Gatton replied. "Whereas here the telephone was installed, so that the bell could be rung by some one merely calling up your number—and the ringing stopped by the caller telling the exchange he had made a mistake—in the Red House, as I have discovered, the 'phone had been disconnected shortly after Dr. Brown-Edwards left the place."
"Then the opening and closing of the doors was merely a device for ringing the bell?"