n the gray darkness the curved fangs of a saber-toothed tiger gleamed white and ghostly. The man-figure that stood half crouched in the mouth of the cave involuntarily shivered.

"Gwanga!" he said. "He goes, too!"

But the man did not move more than to shift a club to his right hand. Heavy, that club, and knotted and with a head of stone tied and wrapped with leather thongs; but Gor of the tribe of Zoran swung it easily with one of his long arms. He paid only casual attention as the great cat passed on into the night.

One leathery hand was raised to shield his slitted eyes; the wind from the north struck toward the mouth of the cave, and it brought with it cold driving rain and whirling flurries of frozen pellets that bit and stung.

Snow! Gor had traveled far, but never had he seen a storm like this with white cold in the air. Again a shiver that was part fear rippled through his muscles and gripped with invisible fingers at his knotted arms.

"The Beast of the North is angry!" he told himself.

Through the dark and storm, animals drifted past before the blasts of cold. They were fleeing; they were full of fear—fear of something that the dull mind of Gor could not picture. But in that mind was the same wordless panic.

Gor, the man-animal of that pre-glacial day, stared wondering, stupidly, into the storm with eyes like those of the wild pig. His arms were long, almost to his knees; his hair, coarse and matted, hung in greasy locks about his savage face. Behind his low, retreating forehead was place for little of thought or reason. Yet Gor was a man, and he met the threat of disaster by something better than blind, terrified, animal flight.

A scant hundred in the tribe—men and women and little pot-bellied brown children—Gor gathered them together in the cave far back from the mouth.

"For many moons," he told them by words and signs, "the fear has been upon us. There have been signs for us to see and for all the Four-feet—for Hathor, the great, and for little Wahti in his hole in the sand-hill. Hathor has swung his long snout above his curved tusks and has cried his fear, and the Eaters of the Dead have circled above him and cried their cry.

"And now the Sun-god does not warm us. He has gone to hide behind the clouds. He is afraid—afraid of the cold monster that blows white stinging things in his breath.

"The Sun-god is gone—now, when he should be making hot summer! The Four-feet are going. Even Gwanga, the long-toothed, puts his tail between his legs and runs from the cold."

he naked bodies shivered in the chill that struck in from the storm-wrapped world; they drew closer their coverings of fur and hides. The light of their flickering fires played strange tricks with their savage faces to make them still uglier and to show the dull terror that gripped them.

"Run—we must run—run away—the breath of the beast is on us—he follows close—run...." Through the mutterings and growls a sick child whimpered once, then was still. Gor was speaking again:

"Run! Run away!" he mocked them. "And where shall the tribe of Zoran go? With Gwanga, to make food for his cat belly or to be hammered to death with the stones of the great tribes of the south?"

There was none to reply—only a despairing moan from ugly lips. Gor waited, then answered his own question.

"No!" he shouted, and beat upon his hairy chest that was round as the trunk of a tree. "Gor will save you—Gor, the wanderer! You named me well: my feet have traveled far. Beyond the red-topped mountains of the north I have gone; I have seen the tribes of the south, and I brought you a head for proof. I have followed the sun, and I have gone where it rises."

In the half light, coarse strands of hair waved as hideous heads were nodded in confirmation of the boast, though many still drooped despairingly.

"If Gor leads, where will he go?" a voice demanded.

Another growled: "Gor's feet have gone far: where have they gone where the Beast cannot follow our scent?"

"Down!" said Gor with unconscious dramatic effect, and he pointed at the rocky floor of the cave. "I have gone where even the Beast of the North cannot go. The caves back of this you have seen, but only Gor has seen the hole—the hole where a strong man can climb down; a hole too small for the great beast to get through. Gor has gone down to find more caves below and more caves below them.

"Far down is a place where it is always warm. There is water in lakes and streams. Gor has caught fish in that water, and they were good. There are growing things like the round earth-plants that come in the night, and they, too, were good.

"Will you follow Gor?" he demanded. "And when the Beast is gone and the Sun-god comes back we will return—"

he blast that found its way inside the cave furnished its own answer; the echoing, "We follow! We follow!" spoken through chattering teeth was not needed. The women of the tribe shivered more from the cold than from fear as they gathered together their belongings, their furs and hides and crude stone implements; and the shambling man-shape, called Gor, led them to the hole down which a strong man might climb, led them down and still down....

But, as to the rest—Gor's promise of safe return to the light of day and that outer world where the Sun-god shone—how was Gor to know that a mighty glacier would lock the whole land in ice for endless years, and, retreating, leave their upper caves filled and buried under a valley heaped with granite rocks?

Even had the way been open to the land above, Gor himself could never have known when that ice-sheet left. For when that day came and once more the Sun-god drew steamy spirals from the drenched and thawing ground, Gor, deep down in the earth, had been dead for countless years. Only the remote descendants of that earlier tribe now lived in their subterranean home, though even with them there were some who spoke at times of those legends of another world which their ancestors had left.

And through the long centuries, while evolution worked its slow changes, they knew nothing of the vanishing ice, of the sun and the gushing waters, the grass and forests that came to cover the earth. Nor did their descendants, exploring interminable caves, learning to tame the internal fires, always evolving, always growing, have any remote conception of a people who sailed strange seas to find new lands and live and multiply and build up a country of sky-reaching cities and peaceful farmlands, of sunlit valleys and hills.

But always there were adventurous souls who made their way deeper and deeper into the earth; and among them in every generation was one named Gor who was taught the tribal legends and who led the adventurers on. But legends have a trick of changing, and instead of searching upward, it was through the deeper strata that they made their slow way in their search for a mystic god and the land of their fathers' fathers....