"... that's my half of it. The rest of it you know." Ross held his hands close to the small fire sheltered in the pit he had helped dig and flexed his cold-numbed fingers in the warmth.

From across the handful of flames Ashe's eyes, too bright in a fever-flushed face, watched him demandingly. The fugitives had taken cover in an angle where the massed remains of an old avalanche provided a cave-pocket. McNeil was off scouting in the gray drizzle of the day, and their escape from the village was now some forty-eight hours behind them.

"So the crackpots were right, after all. They only had their times mixed." Ashe shifted on the bed of brush and leaves they had raked together for his comfort.

"I don't understand——"

"Flying saucers," Ashe returned with an odd little laugh. "It was a wild possibility, but it was on the books from the start. This certainly will make Kelgarries turn red——"

"Flying saucers?"

Ashe must be out of his head from the fever, Ross supposed. He wondered what he should do if Ashe tried to get up and walk away. He could not tackle a man with a bad hole in his shoulder, nor was he certain he could wrestle Ashe down in a real fight.

"That globe-ship was never built on this world. Use your head, Murdock. Think about your furry-faced friend and the baldy with him. Did either look like normal Terrans to you?"

"But—a spaceship!" It was something that had so long been laughed to scorn. When men had failed to break into space after the initial excitement of the satellite launchings, space flight had become a matter for jeers. On the other hand, there was the evidence collected by his own eyes and ears, his own experience. The services of the lifeboat had been techniques outside of his experience.

"This was insinuated once"—Ashe was lying flat now, gazing speculatively up at the projection of logs and earth which made them a partial roof—"along with a lot of other bright ideas, by a gentleman named Charles Fort, who took a lot of pleasure in pricking what he considered to be vastly over-inflated scientific pomposity. He gathered together four book loads of reported incidents of unexplainable happenings which he dared the scientists of his day to explain. And one of his bright suggestions was that such phenomena as the vast artificial earthworks found in Ohio and Indiana were originally thrown up by space castaways to serve as SOS signals. An intriguing idea, and now perhaps we may prove it true."

"But if such spaceships were wrecked on this world, I still don't see why we didn't find traces of them in our own time."

"Because that wreck you explored was bedded in a glacial era. Do you have any idea how long ago that was, counting from our own time? There were at least three glacial periods—and we don't know in which one the Reds went visiting. That age began about a million years before we were born, and the last of the ice ebbed out of New York State some thirty-eight thousand years ago, boy. That was the early Stone Age, reckoning it by the scale of human development, with an extremely thin population of the first real types of man clinging to a few warmer fringes of wilderness.

"Climatic changes, geographical changes, all altered the face of our continents. There was a sea in Kansas; England was part of Europe. So, even though as many as fifty such ships were lost here, they could all have been ground to bits by the ice flow, buried miles deep in quakes, or rusted away generations before the first really intelligent man arrived to wonder at them. Certainly there couldn't be too many such wrecks to be found. What do you think this planet was, a flypaper to attract them?"

"But if ships crashed here once, why didn't they later when men were better able to understand them?" Ross countered.

"For several reasons—all of them possible and able to be fitted into the fabric of history as we know it on this world. Civilizations rise, exist, and fall, each taking with it into the limbo of forgotten things some of the discoveries which made it great. How did the Indian civilizations of the New World learn to harden gold into a useable point for a cutting weapon? What was the secret of building possessed by the ancient Egyptians? Today you will find plenty of men to argue these problems and half a hundred others.

"The Egyptians once had a well-traveled trade route to India. Bronze Age traders opened up roads down into Africa. The Romans knew China. Then came an end to each of these empires, and those trade routes were forgotten. To our European ancestors of the Middle Ages, China was almost a legend, and the fact that the Egyptians had successfully sailed around the Cape of Good Hope was unknown. Suppose our space voyagers represented some star-born confederacy or empire which lived, rose to its highest point, and fell again into planet-bound barbarism all before the first of our species painted pictures on a cave wall?

"Or take it that this world was an unlucky reef on which too many ships and cargoes were lost, so that our whole solar system was posted, and skippers of star ships thereafter avoided it? Or they might even have had some rule that when a planet developed a primitive race of its own, it was to be left strictly alone until it discovered space flight for itself."

"Yes." Every one of Ashe's suppositions made good sense, and Ross was able to believe them. It was easier to think that both Furry-face and Baldy were inhabitants of another world than to think their kind existed on this planet before his own species was born. "But how did the Reds locate that ship?"

"Unless that information is on the tapes we were able to bring along, we shall probably never know," Ashe said drowsily. "I might make one guess—the Reds have been making an all-out effort for the past hundred years to open up Siberia. In some sections of that huge country there have been great climatic changes almost overnight in the far past. Mammoths have been discovered frozen in the ice with half-digested tropical plants in their stomach. It's as if the beasts were given some deep-freeze treatment instantaneously. If in their excavations the Reds came across the remains of a spaceship, remains well enough preserved for them to realize what they had discovered, they might start questing back in time to find a better one intact at an earlier date. That theory fits everything we know now."

"But why would the aliens attack the Reds now?"

"No ship's officers ever thought gently of pirates." Ashe's eyes closed.

There were questions, a flood of them, that Ross wanted to ask. He smoothed the fabric on his arm, that stuff which clung so tightly to his skin yet kept him warm without any need for more covering. If Ashe were right, on what world, what kind of world, had that material been woven, and how far had it been brought that he could wear it now?

Suddenly McNeil slid into their shelter and dropped two hares at the edge of the fire.

"How goes it?" he said, as Ross began to clean them.

"Reasonably well," Ashe, his eyes still closed, replied to that before Ross could. "How far are we from the river? And do we have company?"

"About five miles—if we had wings." McNeil answered in a dry tone. "And we have company all right, lots of it!"

That brought Ashe up, leaning forward on his good elbow. "What kind?"

"Not from the village." McNeil frowned at the fire which he fed with economic handfuls of sticks. "Something's happening on this side of the mountains. It looks as if there's a mass migration in progress. I counted five family clans on their way west—all in just this one morning."

"The village refugees' stories about devils might send them packing," Ashe mused.

"Maybe." But McNeil did not sound convinced. "The sooner we head downstream, the better. And I hope the boys will have that sub waiting where they promised. We do possess one thing in our favor—the spring floods are subsiding."

"And the high water should have plenty of raft material." Ashe lay back again. "We'll make those five miles tomorrow."

McNeil stirred uneasily and Ross, having cleaned and spitted the hares, swung them over the flames to broil. "Five miles in this country," the younger man observed, "is a pretty good day's march"—he did not add as he wanted to—"for a well man."

"I will make it," Ashe promised, and both listeners knew that as long as his body would obey him he meant to keep that promise. They also knew the futility of argument.

Ashe proved to be a prophet to be honored on two counts. They did make the trek to the river the next day, and there was a wealth of raft material marking the high-water level of the spring flood. The migrations McNeil had reported were still in progress, and the three men hid twice to watch the passing of small family clans. Once a respectably sized tribe, including wounded men, marched across their route, seeking a ford at the river.

"They've been badly mauled," McNeil whispered as they watched the people huddled along the water's edge while scouts cast upstream and down, searching for a ford. When they returned with the news that there was no ford to be found, the tribesmen then sullenly went to work with flint axes and knives to make rafts.

"Pressure—they are on the run." Ashe rested his chin on his good forearm and studied the busy scene. "These are not from the village. Notice the dress and the red paint on their faces. They're not like Ulffa's kin either. I wouldn't say they were local at all."

"Reminds me of something I saw once—animals running before a forest fire. They can't all be looking for new hunting territory," McNeil returned.

"Reds sweeping them out," Ross suggested. "Or could the ship people—?"

Ashe started to shake his head and then winced. "I wonder...." The crease between his level brows deepened. "The ax people!" His voice was still a whisper, but it carried a note of triumph as if he had fitted some stubborn jigsaw piece into its proper place.

"Ax people?"

"Invasion of another people from the east. They turned up in prehistory about this period. Remember, Webb spoke of them. They used axes for weapons and tamed horses."

"Tartars"—McNeil was puzzled—"This far west?"

"Not Tartars, no. You needn't expect those to come boiling out of middle Asia for some thousands of years yet. We don't know too much about the ax people, save that they moved west from the interior plains. Eventually they crossed to Britain; perhaps they were the ancestors of the Celts who loved horses too. But in their time they were a tidal wave."

"The sooner we head downstream, the better." McNeil stirred restlessly, but they knew that they must keep to cover until the tribesmen below were gone. So they lay in hiding another night, witnessing on the next morning the arrival of a smaller party of the red-painted men, again with wounded among them. At the coming of this rear guard the activity on the river bank rose close to frenzy.

The three men out of time were doubly uneasy. It was not for them to merely cross the river. They had to build a raft which would be water-worthy enough to take them downstream—to the sea if they were lucky. And to build such a sturdy raft would take time, time they did not have now.

In fact, McNeil waited only until the last tribal raft was out of bow shot before he plunged down to the shore, Ross at his heels. Since they lacked even the stone tools of the tribesmen, they were at a disadvantage, and Ross found he was hands and feet for Ashe, working under the other's close direction. Before night closed in they had a good beginning and two sets of blistered hands, as well as aching backs.

When it was too dark to work any longer, Ashe pointed back over the track they had followed. Marking the mountain pass was a light. It looked like fire, and if it was, it must be a big one for them to be able to sight it across this distance.

"Camp?" McNeil wondered.

"Must be," Ashe agreed. "Those who built that blaze are in such numbers that they don't have to take precautions."

"Will they be here by tomorrow?"

"Their scouts might, but this is early spring, and forage can't have been too good on the march. If I were the chief of that tribe, I'd turn aside into the meadow land we skirted yesterday and let the herds graze for a day, maybe more. On the other hand, if they need water——"

"They will come straight ahead!" McNeil finished grimly. "And we can't be here when they arrive."

Ross stretched, grimacing at the twinge of pain in his shoulders. His hands smarted and throbbed, and this was just the beginning of their task. If Ashe had been fit, they might have trusted to logs for support and swum downstream to hunt a safer place for their shipbuilding project. But he knew that Ashe could not stand such an effort.

Ross slept that night mainly because his body was too exhausted to let him lie awake and worry. Roused in the earliest dawn by McNeil, they both crawled down to the water's edge and struggled to bind stubbornly resisting saplings together with cords twisted from bark. They reinforced them at crucial points with some strings torn from their kilts, and strips of rabbit hide saved from their kills of the past few days. They worked with hunger gnawing at them, having no time now to hunt. When the sun was well westward they had a clumsy craft which floated sluggishly. Whether it would answer to either pole or improvised paddle, they could not know until they tried it.

Ashe, his face flushed and his skin hot to the touch, crawled on board and lay in the middle, on the thin heap of bedding they had put there for him. He eagerly drank the water they carried to him in cupped hands and gave a little sigh of relief as Ross wiped his face with wet grass, muttering something about Kelgarries which neither of his companions understood.

McNeil shoved off and the bobbing craft spun around dizzily as the current pulled it free from the shore. They made a brave start, but luck deserted them before they had gotten out of sight of the spot where they embarked.

Striving to keep them in mid-current, McNeil poled furiously, but there were too many rocks and snagged trees projecting from the banks. Sharing that sweep of water with them, and coming up fast, was a full-sized tree. Twice its mat of branches caught on some snag, holding it back, and Ross breathed a little more freely, but it soon tore free again and rolled on, as menacing as a battering ram.

"Get closer to shore!" Ross shouted the warning. Those great, twisted roots seemed aimed straight at the raft, and he was sure if that mass struck them fairly, they would not have a chance. He dug in with his own pole, but his hasty push did not meet bottom; the stake in his hands plunged into some pothole in the hidden river bed. He heard McNeil cry out as he toppled into the water, gasping as the murky liquid flooded his mouth, choking him.

Half dazed by the shock, Ross struck out instinctively. The training at the base had included swimming, but to fight water in a pool under controlled conditions was far different from fighting death in a river of icy water when one had already swallowed a sizable quantity of that flood.

Ross had a half glimpse of a dark shadow. Was it the edge of the raft? He caught at it desperately, skinning his hands on rough bark, dragged on by it. The tree! He blinked his eyes to clear them of water, to try to see. But he could not pull his exhausted body high enough out of the water to see past the screen of roots; he could only cling to the small safety he had won and hope that he could rejoin the raft somewhere downstream.

After what seemed like a very long time he wedged one arm between two water-washed roots, sure that the support would hold his head above the surface. The chill of the stream struck at his hands and head, but the protection of the alien clothing was still effective, and the rest of his body was not cold. He was simply too tired to wrest himself free and trust again to the haphazard chance of making shore through the gathering dusk.

Suddenly a shock jarred his body and strained the arm he had thrust among the roots, wringing a cry out of him. He swung around and brushed footing under the water; the tree had caught on a shore snag. Pulling loose from the roots, he floundered on his hands and knees, falling afoul of a mass of reeds whose roots were covered with stale-smelling mud. Like a wounded animal he dragged himself through the ooze to higher land, coming out upon an open meadow flooded with moonlight.

For a while he lay there, his cold, sore hands under him, plastered with mud and too tired to move. The sound of a sharp barking aroused him—an imperative, summoning bark, neither belonging to a wolf nor a hunting fox. He listened to it dully and then, through the ground upon which he lay, Ross felt as well as heard the pounding of hoofs.

Hoofs—horses! Horses from over the mountains—horses which might mean danger. His mind seemed as dull and numb as his hands, and it took quite a long time for him to fully realize the menace horses might bring.

Getting up, Ross noticed a winged shape sweeping across the disk of the moon like a silent dart. There was a single despairing squeak out of the grass about a hundred feet away, and the winged shape arose again with its prey. Then the barking sound once more—eager, excited barking.

Ross crouched back on his heels and saw a smoky brand of light moving along the edge of the meadow where the band of trees began. Could it be a herd guard? Ross knew he had to head back toward the river, but he had to force himself on the path, for he did not know whether he dared enter the stream again. But what would happen if they hunted him with the dog? Confused memories of how water spoiled scent spurred him on.

Having reached the rising bank he had climbed so laboriously before, Ross miscalculated and tumbled back, rolling down into the mud of the reed bed. Mechanically he wiped the slime from his face. The tree was still anchored there; by some freak the current had rammed its rooted end up on a sand spit.

Above in the meadow the barking sounded very close, and now it was answered by a second canine belling. Ross wormed his way back through the reeds to the patch of water between the tree and the bank. His few poor efforts at escape were almost half-consciously taken; he was too tired to really care now.

Soon he saw a four-footed shape running along the top of the bank, giving tongue. It was then joined by a larger and even more vocal companion. The dogs drew even with Ross, who wondered dully if the animals could sight him in the shadows below, or whether they only scented his presence. Had he been able, he would have climbed over the log and taken his chances in the open water, but now he could only lie where he was—the tangle of roots between him and the bank serving as a screen, which would be little enough protection when men came with torches.

Ross was mistaken, however, for his worm's progress across the reed bed had liberally besmeared his dark clothing and masked the skin of his face and hands, giving him better cover than any he could have wittingly devised. Though he felt naked and defenseless, the men who trailed the hounds to the river bank, thrusting out the torch over the edge to light the sand spit, saw nothing but the trunk of the tree wedged against a mound of mud.

Ross heard a confused murmur of voices broken by the clamor of the dogs. Then the torch was raised out of line of his dazzled eyes. He saw one of the indistinct figures above cuff away a dog and move off, calling the hounds after it. Reluctantly, still barking, the animals went. Ross, with a little sob, subsided limply in the uncomfortable net of roots, still undiscovered.