* * * * * They followed him into the chamber, which was soon illumined fitfully by a smoky kerosene lamp. Both took a rapid survey of the place. Conceivably it might have been the scene of scientific experiments, but its aspect surely belied such a supposition. The average imagination would instantly pronounce it the abode of a maniac, or the lair of an alchemist. Again, that it might be the laboratory of an extremely slovenly veterinary was suggested by the several filthy cages to be seen resting against the wall. All of these were unoccupied except one in a dark corner, from which issued a sound of contented purring, evidently telling of some well-satisfied cat. The air was close and foul, being heavy with the odor of musty, decaying drugs. In every possible niche and cranny the omnipresent dust had settled in a uniform sheen of gray which showed but few signs of recent disturbance. "Here, gentlemen," their host was saying, "is where I carry on my work. It is rather gloomy here after dark, but then I do not spend much time here during the night. I have decided to acquaint you with some of the details of one or two of my experiments. Doubtless you will find them interesting." While speaking he had, mechanically it seemed, reached for a glass humidor in which were perhaps a dozen cigars. Silently he selected one and extended the rest to the two visitors. After all three had puffed for a moment at the weeds, the old man began to talk, rapidly it seemed to them. Perry from time to time took notes, as the old man proceeded, an expression of utter amazement gradually overspreading his face. Handlon pulled away contentedly at his cigar, and on his features there grew an almost ludicrous expression of well-being. Was the simple photographer so completely at ease that he had at length forsaken all thought of possible danger? As Professor Kell talked on he seemed to warm to his subject. At the end of five minutes he began uncovering a peculiar apparatus which had rested beneath the massive old table before which they were sitting. The two men caught the flash of light on glass, and a jumble of coiled wires became visible. * * * * * Was the air in the laboratory getting unbearably close? Or was the queer leaden feeling that had taken possession of Perry's lungs but an indication of his overpowering weariness? He felt a steadily increasing irritation, as if for some strange reason he suddenly resented the words of their host, which seemed to be pouring out in an endless stream. The cigar had, paradoxically, an oddly soothing quality, and he puffed away in silence.