"But how?" I implored. "How can it be? There's no way into this thing. Perhaps he was working here, and the stone came loose from its setting. He couldn't have dropped it after the cage was completed." "It's his diamond, sir," intoned the old man, dully. "I know it is." Then a sudden unreasoning terror filled me. I shrank away from that shining box. It seemed to be mocking me, gloatingly, malevolently. "Quickly!" I threw at the aged couple. "Let us get out of here! Now! At once!" They needed no second urging. I knew that they felt as I felt: the laboratory was a sepulcher! Five minutes later I was guiding my car over the narrow road to town. I did not pause until I drew up at police headquarters. I suppose my appearance was distraught, for I was ushered into the presence of the chief without delay. In a few moments I had poured out my story. He listened with a polite calmness I found almost maddening. Leaning back in his chair, he reviewed, audibly, the facts. "Some twenty-odd years ago your friend, Professor Wroxton, married. He was so absorbed in the pursuit of some weird invention that he neglected his bride. She ran away with another man. This man deserted her, and disappeared. The professor found her many months later, in desperate health. Shortly afterwards she died. Your friend tried to trail the man, but failed. Shocked and saddened beyond measure, he retired to a place known as The Grange." * * * * * He suddenly straightened up in his seat, and pointed at me a thick forefinger. "How long have you known Professor Wroxton?" "About ten years," I answered. "What was he trying to invent?" "I don't know," I replied. "And yet you had his confidence in other matters?" "But what has all this to do with finding out what has become of my friend?" I blurted out. "Perhaps every moment counts." "A lot." The chief eyed me in a way I did not like. "Solely because your friend has not been seen by his servants for nearly twenty-four hours, merely because you saw what you believe to be his diamond in some kind of a glass compartment in his laboratory, you come here as distraught as a man who has something terrible on his mind. Why?" "I can't say." I shifted uneasily under that direct stare. "Somehow I _feel_ that something dreadful has happened to my friend." "We do not go by _feelings_." The chief got to his feet. "But you have told me enough to warrant action. I want you to guide me and a couple of men to this house. Please wait here until I return." He left the room.