And still there persisted that abnormal coolness that made him almost light-headed, almost carefree. Even the fetid stench ceased to offend. His feet moved with never a sound to find the first step--and the next--and the next. He must go cautiously; he must not betray his presence until he was ready to strike. Just where that blow would be delivered or against what adversary he could not tell, and perhaps it would be given him only to save Diane and Walt by the grace of a merciful bullet. It made no difference. Nothing made any difference any more; they had had their day, and now if the night came suddenly that was all he could ask. And still his cautious feet were carrying him down and yet down.... * * * * * He was far below the surface of the ground when he found the foot of the stairs. They had been a spiral; his hand had touched one wall that led him smoothly around a shaft like a great well. And now there was firm rock beneath his feet, where, with one hand still guiding him along the stone wall, he followed the wall into a darkness that was an almost solid, opaque black. He seemed lost in a great void, smothered in silence, and buried under the black weight of the pressing dark, until the sound of a footfall gave him sense of direction and of distance. It made soft echoings along rock walls that picked up every slightest rustle, and Chet realized again how cautious his own advance must be. It came toward him, soft, scuffing, followed the wall where he stood ... and Chet felt that approaching presence almost upon him before he stepped silently out and away. And in the darkness that blotted out his sight he sensed with some inner eye the passing ape-man with arms rigidly extended, while a wave of thankfulness flooded him as he realized that in the dark the brute was as blind as himself and that the terrible thing that had sent him could see at a distance only with the ape-man's eyes. Here was something definite to count on. As long as he remained silent, as long as he kept himself hidden, he was safe. The scuffling footsteps had gone to nothing in the distance when Chet reached out for the wall and went swiftly, carefully, on. The messenger had come this way; he could hurry now that he knew there was safe footing in the dark. The wall ended in a sharp corner; it formed a right angle, and the new surface went on and away from him. Chet was debating whether he should follow or should cast out into the darkness when his staring eyes found the first touch of light. * * * * *