"Not to be too hopeful—" McNeil rubbed his arm across his hot face—"so far, so good." After kicking from his path some of the branches Ross had lopped from the trees they had been felling, he went to help his companion roll another small log up to a shelter which was no longer temporary. If there had been any eyes other than the woodland hunters' to spy upon them, they would have seen only the usual procedure of the Beaker traders, busily constructing one of their posts.

That they were being watched by the hunters, all three were certain. That there might be other spies in the forest, they had to assume for their own safety. They might prowl at night, but in the daytime all of the time agents kept within the bounds of the roles they were acting.

Barter with the head men of the hunting clan had brought those shy people into the camp of the strangers who had such wonders to exchange for tanned deer hides and better furs. The news of the traders' arrival spread quickly during the short time they had been here, so that two other clans had sent men to watch the proceedings.

With the trade came news which the agents sifted and studied. Each of them had a list of questions to insert into their conversations with the tribesmen if and when that was possible. Although they did not share a common speech with the forest men, signs were informative and certain nouns could be quickly learned. In the meantime Ashe became friendly with the nearest and first of the clan groups they discovered, going hunting with the men as an excuse to penetrate the unknown section they must quarter in their search for the Red base.

Ross drank river water and mopped his own hot face. "If the Reds aren't traders," he mused aloud, "what is their cover?"

McNeil shrugged. "A hunting tribe—fishermen—"

"Where would they get the women and children?"

"The same way they get their men—recruit them in our own time. Or in the way lots of tribes grew during periods of stress."

Ross set down the water jug. "You mean, kill off the men, take over their families?" This was a cold-bloodedness he found sickening. Although he had always prided himself on his toughness, several times during his training at the project he had been confronted by things which shook his belief in his own strong stomach and nerve.

"It has been done," McNeil remarked bleakly, "hundreds of times by invaders. In this setup—small family clans, widely scattered—that move would be very easy."

"They would have to pose as farmers, not hunters," Ross pointed out. "They couldn't move a base around with them."

"All right, so they set up a farming village. Oh, I see what you mean—there isn't any village around here. Yet they are here, maybe underground."

How right their guesses were they learned that night when Ashe returned, a deer's haunch on his shoulder. Ross knew him well enough by now to sense his preoccupation. "You found something?"

"A new set of ghosts," Ashe replied with a strange little smile.

"Ghosts!" McNeil pounced upon that. "The Reds like to play the supernatural angle, don't they? First the voice of Lurgha and now ghosts. What do these ghosts do?"

"They inhabit a bit of mountainous territory southeast of here, a stretch strictly taboo for all hunters. We were following a bison track until the beast headed for the ghost country. Then Ulffa called us off in a hurry. It seems that the hunter who goes in there after his quarry never reappears, or if he does, it's in a damaged condition, blown upon by ghosts and burned to death! That's one point."

He sat down by the fire and stretched his arms wearily. "The second is a little more disturbing for us. A Beaker camp about twenty miles south of here, as far as I can judge, was exterminated just a week ago. The message was passed to me because I was thought to be a kinsman of the slain——"

McNeil sat up. "Done because they were hunting us?"

"Might well be. On the other hand, the affair may have been just one of general precaution."

"The ghosts did it?" Ross wanted to know.

"I asked that. No, it seems that strange tribesmen overran it at night."

"At night?" McNeil whistled.

"Just so." Ashe's tone was dry. "The tribes do not fight that way. Either someone slipped up in his briefing, or the Reds are overconfident and don't care about the rules. But it was the work of tribesmen, or their counterfeits. There is also a nasty rumor speeding about that the ghosts do not relish traders and that they might protest intrusions of such with penalties all around——"

"Like the Wrath of Lurgha," supplied Ross.

"There is a certain repetition in this which suggests a lot to the suspicious mind," Ashe agreed.

"I'd say no more hunting expeditions for the present," McNeil said. "It is too easy to mistake a friend for a deer and weep over his grave afterward."

"That is a thought which entered my mind several times this afternoon," Ashe agreed. "These people are deceptively simple on the surface, but their minds do not work along the same patterns as ours. We try to outwit them, but it takes only one slip to make it fatal. In the meantime, I think we'd better make this place a little more snug, and it might be well to post sentries as unobtrusively as possible."

"How about faking some signs of a ruined camp and heading into the blue ourselves?" McNeil asked. "We could strike for the ghost mountains, traveling by night, and Ulffa's crowd would think we were finished off."

"An idea to keep in mind. The point against it would be the missing bodies. It seems that the tribesmen who raided the Beaker camp left some very distasteful evidence of what happened to the camp's personnel. And those we can't produce to cover our trail."

McNeil was not yet convinced. "We might be able to fake something along that line, too——"

"We may have to fake nothing," Ross cut in softly. He was standing close to the edge of the clearing where they were building their hut, his hand on one of the saplings in the palisade they had set up so laboriously that day. Ashe was beside him in an instant.

"What is it?"

Ross's hours of listening to the sounds of the wilderness were his measuring gauge now. "That bird has never called from inland before. It is the blue one we've seen fishing for frogs along the river."

Ashe, not even glancing at the forest, went for the water jug. "Get your trail supplies," he ordered.

Their leather pouches which held enough iron rations to keep them going were always at hand. McNeil gathered them from behind the fur curtain fronting their half-finished cabin. Again the bird called, its cry piercing and covering a long distance. Ross could understand why a careless man would select it for the signal. He crossed the clearing to the donkeys' shelter, slashing through their nose halters. Probably the patient little beasts would swiftly fall victims to some forest prowlers, but at least they would have their chance to escape.

McNeil, his cloak slung about him to conceal the ration bags, picked up the leather bucket as if he were merely going down to the river for water, and came to join Ross. They believed that they were carrying it off well, that the camp must appear normal to any lurkers in the woods. But either they had made some slip or the enemy was impatient. An arrow sped out of the night to flash across the fire, and Ashe escaped death only because he had leaned forward to feed the flames. His arm swung out and sent the water in the jar hissing onto the blaze as he himself rolled in the other direction.

Ross plunged for the brush with McNeil. Lying flat on the half-frozen ground, they started to work their way to the river bank where the open area would make surprise less possible.

"Ashe?" he whispered and felt McNeil's warm breath on his cheek as he replied:

"He'll make it the other way! He's the best we have for this sort of job."

They made a worm's progress, twice lying, with dagger in hand, while they listened to a faint rustle which betrayed the passing of one of the attackers. Both times Ross was tempted to rise and try to cut off the stranger, but he fought down the impulse. He had learned a control of himself that would have been impossible for him a few months earlier.

The glimmer of the river was pale through the clumps of bushes which sometimes grew into the flood. In this country winter still clung tenaciously in shadowy places with cups of leftover snow, and there was a bite in the wind and water. Ross rose to his knees with an involuntary gasp as a scream cut through the night. He wrenched around toward the camp, only to feel McNeil's hand clamp on his forearm.

"That was a donkey," whispered McNeil urgently. "Come on, let's go down to that ford we discovered!"

They turned south, daring now to trot, half bent to the ground. The river was swollen with spring floods which were only now beginning to subside, but two days earlier they had noticed a sandbar at one spot. By crossing that shelf across the bed, they might hope to put water between them and the unknown enemy tonight. It would give them a breathing space, even though Ross privately shrank from the thought of plowing into the stream. He had seen good-sized trees swirling along in the current only yesterday. And to make such a dash in the dark....

From McNeil's throat burst a startling sound which Ross had last heard in Britain—the questing howl of a hunting wolf. The cry was answered seconds later from downstream.

"Ashe!"

They worked their way along the edge of the water with continued care, until they came upon Ashe at last, so much a part of his background that Ross started when the lump he had taken for a bush hunched forward to join them. Together they made the river crossing and turned south again to head for the mountains. It was then that disaster struck.

Ross heard no birdcall warning this time. Though he was on guard, he never sensed the approach of the man who struck him down from behind. One moment he had been trailing McNeil and Ashe; the next moment was black nothingness.

He was aware of a throb of pain which carried throughout his body and then localized in his head. Forcing open his eyes, the dazzle of light was like a spear point striking directly into his head, intensifying his pain to agony. He brought his hand up to his face and felt stickiness there.

"Assha—" He believed he called that aloud, but he did not even hear his own voice. They were in a valley; a wolf had attacked him out of the bushes. Wolf? No, the wolf was dead, but then it came alive again to howl on a river bank.

Ross forced his eyes open once more, enduring the pain of beams he recognized as sunshine. He turned his head to avoid the glare. It was hard to focus, but he fought to steady himself. There was some reason why it was necessary to move, to get away. But away from what and where? When Ross tried to think he could only see muddled pictures which had no connection.

Then a moving object crossed his very narrow field of vision, passing between him and a thing he knew was a tree trunk. A four-footed creature with a red tongue hanging from its jaws. It came toward him stiff-legged, growling low in its throat, and sniffed at his body before barking in short excited bursts of sound.

The noise hurt his head so much that Ross closed his eyes. Then a shock of icy liquid thrown into his face aroused him to make a feeble protest and he saw, hanging over him in a strange upside-down way, a bearded face which he knew from the past.

Hands were laid on him and the roughness with which he was moved sent Ross spiraling back into the dark once again. When he aroused for the second time it was night and the pain in his head was dulled. He put out his hands and discovered that he lay on a pile of fur robes, and was covered by one.

"Assha—" Again he tried that name. But it was not Assha who came in answer to his feeble call. The woman who knelt beside him with a horn cup in her hand had neatly braided hair in which gray strands showed silver by firelight. Ross knew he had seen her before, but again where and when eluded him. She slipped a sturdy arm under his head and raised him while the world whirled about. The edge of the horn cup was pressed to his lips, and he drank bitter stuff which burned in his throat and lit a fire in his insides. Then he was left to himself once again and in spite of his pain and bewilderment he slept.

How many days he lay in the camp of Ulffa, tended by the chief's head wife, Ross found it hard to reckon. It was Frigga who had argued the tribe into caring for a man they believed almost dead when they found him, and who nursed Ross back to life with knowledge acquired through half a hundred exchanges between those wise women who were the doctors and priestesses of these roaming peoples.

Why Frigga had bothered with the injured stranger at all Ross learned when he was able to sit up and marshal his bewildered thoughts into some sort of order. The matriarch of the tribe thirsted for knowledge. That same urge which had led her to certain experiments with herbs, had made her consider Ross a challenge to her healing skill. When she knew that he would live she determined to learn from him all he had to give.

Ulffa and the men of the tribe might have eyed the metal weapons of the traders with awe and avid desire, but Frigga wanted more than trade goods. She wanted the secret of the making of such cloth as the strangers wore, everything she could learn of their lives and the lands through which they had come. She plied Ross with endless questions which he answered as best he could, for he lay in an odd dreamy state where only the present had any reality. The past was dim and far away, and while he was now and then dimly aware that he had something to do, he forgot it easily.

The chief and his men prowled the half-built station after the attackers had withdrawn, bringing back with them a handful of loot—a bronze razor, two skinning knives, some fishhooks, a length of cloth which Frigga appropriated. Ross eyed this spoil indifferently, making no claim upon it. His interest in everything about him was often blanked out by headaches which kept him limp on his bed, uncaring and stupid for hours or even full days.

He gathered that the tribe had been living in fear of an attack from the same raiders who had wiped out the trading post. But at last their scouts returned with the information that the enemy had gone south.

There was one change of which Ross was not aware but which might have startled both Ashe and McNeil. Ross Murdock had indeed died under that blow which had left him unconscious beside the river. The young man whom Frigga had drawn back to sense and a slow recovery was Rossa of the Beaker people. This same Rossa nursed a hot desire for vengeance against those who had struck him down and captured his kinsmen, a feeling which the family tribe who had rescued him could well understand.

There was the same old urgency pushing him to try his strength now, to keep to his feet even when they were unsteady. His bow was gone, but Ross spent hours fashioning another, and he traded his copper bracelet for the best dozen arrows in Ulffa's camp. The jet pin from his cloak he presented to Frigga with all his gratitude.

Now that his strength was coming back he could not rest easy in the camp. He was ready to leave, even though the gashes on his head were still tender to the touch. Ulffa indulgently planned a hunt southward, and Rossa took the trail with the tribesmen.

He broke with the clan hunters when they turned aside at the beginning of the taboo land. Ross, his own mind submerged and taken over by his Beaker cover, hesitated too. Yet he could not give up, and the others left him there, his eyes on the forbidden heights, unhappy and tormented by more than the headaches which still came and went with painful regularity. In the mountains lay what he sought—a hidden something within his brain told him that over and over—but the mountains were taboo, and he should not venture into them.

How long he might have hesitated there if he had not come upon the trail, Ross did not know. But on the day after the hunters of Ulffa's clan left, a glint of sunlight striking between two trees pointed out a woodsman's blaze on a third tree trunk. The two halves of Ross's memory clicked together for an instant as he examined that cut. He knew that it marked a trace and he pushed on, hunting a second cut and then a third. Convinced that these would lead him into the unknown territory, Ross's desire to explore overcame the grafted superstitions of his briefing.

There were other signs that this was an often-traveled route: a spring cleared of leaves and walled with stone, a couple of steps cut in the turf on a steep slope. Ross moved warily, alert to any sound. He might not be an expert woodsman, but he was learning fast, perhaps the faster because his false memories now supplanted the real ones.

That night he built no fire, crawling instead into the heart of a rotted log to sleep, awakening once to the call of a wolf and another time at the distant crash of a dead tree yielding to wind.

In the morning he was about to climb back to the trail he had prudently left the night before when he saw five bearded, fur-clad men looking much the same as Ulffa's people. Ross hugged the earth and watched them pass out of sight before he followed.

All that day he wove an up-and-down trail behind the small band, sometimes catching sight of them as they topped a rise well ahead or stopped to eat. It was late afternoon when he crept cautiously to the top of a ridge and gazed down into a valley.

There was a town in that valley, sturdy houses of logs behind a stockade. He had seen towns vaguely like it before, yet it had a dreamlike quality as if it were not as real as it appeared.

Ross rested his chin on his arms and watched that town and the people moving in it. Some were fur-clad hunters, but others dressed quite differently. He started up with a little cry at the sight of one of the men who had walked so swiftly from one house to the next; surely he was a Beaker trader!

His unease grew stronger with every moment he watched, but it was the oddness he sensed in that town which bothered him and not any warning that he, himself, was in danger. He had gotten to his knees to see better when out of nowhere a rope sang through the air, settling about his chest with a vicious jerk which not only drove the air from his lungs but pinioned his arms tight to his body.