the left. The trace
continued down the slope. Now the towering walls of ice and snow were
broken by rocky teeth as if they had bitten deep upon this land, only to
be gnawed in return. Rounding one of those rock fangs, Ross looked at a
stretch of level ground. Snow lay here, but the beaten-down trail led
straight through it to the rounded side of a huge globe half buried in
the ground, a globe of dark material which could only be man-made.

Ross was past caution. He must get to warmth and shelter or he was done
for, and he knew it. Wavering and weaving, he went on, his attention
fixed on the door ahead--a closed oval door. With a sob of exhausted
effort, Ross threw himself against it. The barrier gave, letting him
fall forward into a queer glimmering radiance of bluish light.

The light rousing him because it promised more, he crawled on past
another door which was flattened back against the inner wall. It was
like making one's way down a tube. Ross paused, pressing his lifeless
hands against his bare chest under the edge of his tunic, suddenly
realizing that there was warmth here. His breath did not puff out in
frosty streamers before him, nor did the air sear his lungs when he
ventured to draw in more than shallow gulps.

With that realization a measure of animal caution returned to him. To
remain where he was, just inside the entrance, was to court disaster. He
must find a hiding place before he collapsed, for he sensed he was very
near the end of his ability to struggle. Hope had given him a flash of
false strength, the impetus to move, and he must make the most of that
gift.

His path ended at a wide ladder, coiling in slow curves into gloom below
and shadows above. He sensed that he was in a building of some size. He
was afraid to go down, for even looking in that direction almost
finished his sense of balance, so he climbed up.

Step by step, Ross made that painful journey, passing levels from which
three or four hallways ran out like the radii of a spider's web. He was
close to the end of his endurance when he heard a sound, echoed,
magnified, from below. It was someone moving. He dragged his body into
the fourth level where the light was very faint, hoping to crawl far
enough into one of the passages to remain unseen from the stair. But he
had gone only part-way down his chosen road when he collapsed, panting,
and fell back against the wall. His hands pawed vainly against that
sleek surface. He was falling