Once his shaking fingers touched something which he knew must be the steps leading to the hellish altar, and from this spot he recoiled in loathing. At another time he encountered the pierced slab he had removed, and here his caution became almost pitiful. But he did not come upon the dread aperture to detain him. What had been down there made no sound nor stir. Evidently its crunching of the fallen electric torch had not been good for it. Each time Willett's fingers felt a perforated slab he trembled. His passage over it would sometimes increase the groaning below, but generally it would produce no effect at all, since he moved very noiselessly. Several times during his progress the glow ahead diminished perceptibly, and he realised that the various candles and lamps he had left must be expiring one by one. The thought of being lost in utter darkness without matches amidst this underground world of nightmare labyrinths impelled him to rise to his feet and run, which he could safely do now that he had passed the open pit; for he knew that once the light failed his only hope of rescue and survival would lie in whatever relief party Mr. Ward might send after missing him for a sufficient period. Presently, however, he emerged from the open space into the narrower corridor and definitely located the glow as coming from a door on his right. In a moment he had reached it and was standing once more in young Ward's secret library, trembling with relief, and watching the sputterings of that last lamp which had brought him to safety.