hollow that had gathered soil through the centuries. There were edible mushrooms in the thicket.

The humans ate. Naturally. And here they realized that they were no longer doomed by the creatures in the valley. Since their climb began they had seen no dangerous thing except the one gigantic, motionless web-spider. They had left the valley and its particular dangers behind.

A man exclaimed in naïve astonishment. He was eating raw mushroom at the moment, and his mouth was full. But abruptly it occurred to him that their doom was lifted. He mentioned the fact in a sort of startled wonder.

"We will stay here," he added happily. "There is food."

And Burl regarded him with knitted brows. Burl was well on the way to becoming spoiled. He had tasted power over his folk, and he found himself jealous of any decision by anybody else.

"I go on," he said haughtily. "Now! You may stay behind if you wish—alone!"

He broke off food for the journey. He held out his hand to Saya. He went on. And again he went upward because to go back was to go to the cañon of the unknown killer. And his folk docilely followed him. They did not really reason about it. To follow him had become a pattern, more or less precarious. In time it could become a habit. Over a period of years it could even become a tradition.

The procession marched on and up. Burl noticed that the air seemed clearer, here. It was not the misty, quasi-transparent stuff of the valley. He could see for miles to right and left, and the curvatures of the mountain-face. But he could not see the valley.

Then he realized that the cloud-bank he saw was finite—an object. He had never thought of it specifically before. To him it had seemed simply the sky.

Now he saw an indefinite lower surface which yet definitely hid the heights toward which he moved. He and his followers were less than a thousand feet below it. It appeared to Burl that presently he would run into an obstacle that would simply keep him from going any further. But until that happened he obstinately continued to climb.

The thing which was the sky appeared to stir. It moved. A little higher, and he could see that there were parts of it which were lower than he was. They moved also. But they did not approach him. And he had no experience of anything inimical which did not plunge upon its victims. Therefore he was not afraid.

In fact, a little later he observed that the whiteness retreated before him, and he was pleased. Weak things such as humans fled aside when predators approached. Here was something which fled aside at his approach. His followers undoubtedly observed the same phenomenon. He had killed a spider. He was a remarkable person. This unknown white stuff was afraid of him.

Burl, with bland conceit, marched confidently through the cloud-bank, ever climbing. At its thickest, he could see only feet in each direction, but always when he advanced threateningly upon opacity, it cleared before him.

Presently the gray light grew brighter. Burl and his folk were accustomed to a shadowless illumination such as fungi could endure—the equivalent of a heavily overcast day on an Earth-type planet. Now the mist about him took on a luminosity which was of a different kind. Suddenly he noticed the silence. He had never known even comparative silence before in all his life. His ears had been assailed every minute since he had been born by a din which was the noise of creatures. By stridulations, by chirpings, by screams, or at the least by the clicking of armor or the deep-toned pulsations of wings. He had always lived in the uproar of frenzied struggle. Now, that hellish chorus of shrieks and cries and mating-calls was cut off. The lower surface of the cloud-bank reflected it. Burl and his people moved upward through an unparalleled stillness.

They fell silent, marveling. They heard each other's movements. They could hear each other's voices. But they moved in a vast quietness over stones which here were not even lichen-covered, but glistened with wet. And all about them a golden glow hung in the very air. Stillness, and quietude, and golden light which grew stronger and stronger and stronger....