Vye crawled weakly from the area of a rock outcrop. The sun, reflected from the cliff side, was a lash of fire across his emaciated body. His swollen tongue moved a pebble back and forth in his dry mouth. He stared dimly down the slope to that beckoning platter of water open under the sun, rimmed with the deadly woodland.

What had happened? They had gone to sleep that first night under the ledge of the dried waterfall. And all of the next day was only a haze to him now. They must have moved on, though he could remember nothing, save Hume's odd behavior—dull-eyed silence while stumbling on as a brainless servio-robot, incoherent speech wherein all the words came fast, running together unintelligibly. And for himself—patches of blackout.

At some time they had come to the cave and Hume had collapsed, not rousing in answer to any of Vye's struggles to awaken him. How long they had been there Vye could not tell now. He had the fear of being left alone in this place. With water perhaps Hume could be returned to consciousness, but that was all gone.

Vye believed he could scent the lake, that every breeze up slope brought its compelling enticement. Just in case Hume might awake to a state of semi-consciousness and wander off, Vye tethered him with blanket bonds.

Vye fingered Hume's knife, which had been painstakingly lashed to a trimmed shaft of wood. Since he had emerged from that clouding of mind which still gripped the Hunter, he had done what he could to prepare for another attack from any roving beast. And he also had Hume's ray tube—its single charge to be used only in dire need.

Water! His cracked lips moved, ejected the pebble. Their four empty water bulbs were in the front of his blanket tunic, pressing against his ribs. It was now—or die, because soon he would be too weak to make the attempt at all. He darted for the first stand of bush downhill.

As the brooding silence of the valley continued, he reached the edge of the wood unhindered, intent on his mission with a concentration which shut out everything save his need and the manner of satisfying it.

He squatted in the bush, eyeing the length of woodland ahead. Then he tried the only action he had been able to think out. That beast Hume had killed had been too heavy to swing up in trees. But Vye's own weight now did not prohibit that form of travel.

With spear and ray tube firmly attached to him, Vye climbed into the first tree. A slim chance—but his only defense against a possible ambush. A wild outward swing brought him, heart-thudding, to the next set of limbs. Then he had a piece of luck, a looped vine tied together a whole group of branches from one treetop to the next.

Hand grips, balance, sometimes a walk along a branch—he threaded towards the lake. Then he came to a gap. With hands laced into tendrils, Vye hunched to look down on a beaten ribbon of gray earth—a trail well used by the evidence of its pounded surface.

That area had to be crossed on foot, but his passage through the brush below would leave traces. Only—there was no other way. Vye checked the lashings of his weapons again before leaping. Almost in the same instant his sandals hit the packed earth he was running. His palms skinned raw on rough bark as he somehow scrambled aloft once more.

No more vines, but broad limbs shooting well out. He dropped from one to another-stopped for breath—listened.

The dark gloom of the wood was broken by sunlight. He was at the final ring of trees. To get to the water he must descend again. A dead trunk extended over the water. If he could run out on that and lower the bulb, it could work.

Eerie silence. No flying things, no tree dwelling reptiles or animals, no disturbance of any water creature on the unruffled surface of the lake. Yet the sensation of life, inimical life, lurking in the depths of the wood, under the water, bore in upon him.

Vye made the light leap to the bole of the dead tree, balanced out on it over the water, moving slowly as the trunk settled a little under his weight. He hunkered down, brought out the first bulb tied fast to a blanket string.

The water of the river had been brown, opaque. But here the liquid was not so cloudy. He could see snags of dead branches below its surface.

And something else!

Down in those turgid depths he made out a straight ridge running with a trueness of line which could not be nature's unassisted product. That ridge joined another in a squared corner. He leaned over, strained his eyes to follow through the murk the farther extent of those two ridges. Looked along both pointed protuberances aimed at the surfaces of the lake, like fangs in an open jaw. Down there was something—something artificially fashioned which might be the answer to all their questions. But to venture into the lake himself—he could not do it! If he could bring the Out-Hunter to his senses the other might find the solution to this puzzle.

Vye filled his bulbs, working speedily, but still studying what he could see of the strange erection under the lake. He thought it was curiously free of silt, and its color, as far as he could distinguish, allowing for the dark hue of the water, was light gray—perhaps even white. He lowered his last bulb.

Down in the bleached forest of dead branches, well to one side of the mysterious walls, there was movement, a slow rolling of a shadow so hidden by a stirring of bottom mud that Vye could not make out its true form. But it was rising to the bulb.

Vye hated to lose a single precious drop. Once he might have the luck to make this journey unmolested, a second time the odds could be too high.

A flash—the slowly rising shadow was transformed into a whizzing spear of attack. Vye snapped the bulb out of the water just as a nightmarish, armored head arose on a whiplash of coiled, scaled neck, and a blunt nose thudded against the tree trunk with a hollow boom. Vye clung to his perch as the thing flopped back into deeper water from a froth of beaten foam, leaving a patch of odorous scum and slime to bracelet the waterlogged wood.

He ran for the shelter of the trees to get away. This time there was no rear, no thump of feet in warning. Out of the ground itself, or so it seemed to Vye's startled terror, reared one of the tusked beasts. To reach his tree and its dubious safety he had to wind past that chimera. And the creature waited with a semblance of ease for him to come to it.

Vye brought around his spear. The length of the haft might afford him a fighting chance if he could send the point home in some vulnerable spot. Yet he knew that the beasts were hard to kill.

The mouth opened in a wide grin of menace. Vye noted a telltale tightening of shoulder muscles. It was going to rush for him now with those clawed forepaws out to rip.

To wait was to court disaster. Vye shouted, his battle cry piercing the silence of the lake and wood. He sprang, aiming the spear point at the beast's protuberant belly, and then swerved to the side as the knife bit home, raking his weapon to open a gaping wound.

The spear was jerked from Vye's hold as both those taloned paws closed on it. Then the creature pulled it free, snapped the haft in two. Vye fired a short blast from the ray tube before it could turn on him, saw fur-fuzz afire, as he ran for the tree.

Beneath its branches he looked back. The beast was pawing at the burning fur on its head, and he had perhaps a second or two. He jumped and his fingers caught on the low hanging branch, then he made a superhuman effort, was up out of the path of the thing which rushed blindly for the tree, shrieking in frenzied complaint.

The huge body crashed against the trunk with force which nearly shook Vye from his hold. As the giant forepaws belabored the wood, strove to lift the body from the ground, Vye worked his way out on another branch. In the end it was the shaking of that limb under him which aided his swing to the next tree. And from there he traveled recklessly, intent only on getting out of the woods as fast as he could.

By the noise the beast was still assaulting the tree, and Vye marveled at its vitality, for the belly wound would long ago have killed any creature he knew. Whether it could trace his flight aloft, or whether its howls would bring more of its kind, he could not guess, but every second he could gain was all important now.

At the gap over the trail he hesitated. That path ran in the direction of the open, and to go on foot meant the possibility of greater speed. Vye slipped from the bough, hit the ground, and ran. His ragged lungsful of air came in great gasps and he doubted if he could take the exertion of more tree travel now. He raced down the path.

Those mewling cries were louder, he was sure of it. Now he heard the thump of the beast's blundering pursuit behind him. But its bulk and hurts slowed it. In the open he could find cover behind a rock, use the ray again.

The trees began to thin. Vye summoned power for a last burst of speed, came out of the shadow of the wood as might a dart expelled from a needler. Before him, up slope, was the closed door of the valley. And moving in from the left was another of the blue beasts.

He could not retreat to the trees. But the newcomer was moving with the same ponderous self-confidence its fellow had shown earlier. Vye dodged right, headed for the rocks by the gap. As he pulled himself into that temporary fortification, the wounded beast dragged out of the woods below. He thought it was blind, yet some instinct drove it after him.

Shaking from fatigue, Vye steadied his forearm on the top of the rock, brought up the ray tube. Less than two yards away now was the deceptively open mouth of the gap. If he threw himself at that, would the elasticity of the unseen curtain hurl him back into the claws of the enemy?

He fired his blast at the head of the unwounded beast. It screeched, threw out its arms, and one of those paws struck against its wounded fellow. With a cry, that one flung itself at its companion in the hunt, and they tangled in a body-to-body battle terrible in its utter ferocity. Vye edged along the cliff determined to reach the cave and Hume. And the two blue things seemed intent on finishing each other off.

The one from the wood was done, the fangs of the other ripping out its throat. Tearing viciously the victor made sure of its kill, then its seared head came up, swung about to face Vye. He guessed it was aware of his movements whether it could see or not.

But he was not prepared for the speed of its attacking lunge. Heretofore the creatures had given the impression of brute strength rather than agility. And he had been almost fatally deceived. He jumped backwards, knowing he must elude that attack, for he could not survive hand-to-hand combat with the alien thing.

There was a moment of dazed disorientation, a weird sensation of falling through unstable space in which there had never been and never would be firm footing again. He was rolling across rock—outside the curtain of the gap.

He sat up, the feeling of being adrift in unmeasurable nothingness making him sick, to watch mistily as the blue beast came to a halt. Whimpering it turned, but before it reached the level of the woods, it sagged to its knees, fell face forward and was still, a destructive machine no longer controlled by life.

Vye tried to understand what had happened. He had somehow broken through that barrier which made the valley a prison. For a moment all that mattered was his freedom. Then he looked apprehensively behind him along the road to the open, more than half expecting to see a gathering of the globes, or of the less impressive lowland beasts that acted as herders. But there was nothing.

Freedom! He dragged himself to his feet. Free to go! He slipped Hume's ray tube back into his belt. Hume was still in the valley!

Vye rubbed his shaking hands across his face. Through the barrier and free—but Hume was back there, without a weapon, defenseless against any questing beast able to nose him out. Sickly, without water and protection, he was a dead man even while he still breathed.

Keeping one hand against the wall of the gap in support, Vye started to walk, not out of the gap towards the distant lowlands, but back into the valley, forcing himself to that by his will alone and screaming inside against such suicidal folly. He put out his hand tentatively when he reached the two points of rock where that curtain had hung. There was no obstruction—the barrier was down! He must get back to Hume.

Still keeping his wall hold, Vye lurched through the gate, was once more in the valley. He stood swaying, listening. But once again there was silence, not even the wind moved through trees or bushes. Placing one foot carefully before the other he went on towards Hume's cave. The haze which had clouded his thinking processes since that first morning's awakening in this bowl was gone now. Except for the physical weakness that weighted his body, he felt once more entirely alive and alert.

Wriggling in the cave's entrance was the Hunter. He had freed the bonds Vye had put on his legs, but his hands were still tied. His face, grimy, sweat-covered, was turned up to the sunlight, and his eyes were again bright with reason.

Vye found the strength to run the last few feet between them. He was fumbling with those ties about Hume's wrists as he blurted out the news. The barrier was out—they could go.

Then he was bringing one of those precious bulbs, raising it to Hume's eager mouth, squeezing a portion of its contents between the man's cracked and bleeding lips.

Somehow they made that trip back to the valley gate. When they saw their goal, Hume broke from Vye's hold, tottered forward with a cry not far removed from a sob. He rebounded to slip full length to the ground and lie there. Sobbing dryly, his gaunt face, eyes closed, turned up to the sky. The trap had snapped shut once again.

"Why—why?" Vye found he was repeating the same words over and over, his gaze blank, unfocussed, yet turned to the woods of the lake.

"Tell me what happened again."

Vye's head came around. Hume had pulled himself up so that his shoulders rested against the rock wall. His plasta-hand was out-flung, slipping up and down what seemed empty air, but which was the barrier against freedom. And now his eyes seemed entirely sane.

Slowly, hesitating between words, Vye went over the full account of his visit to the lake, his retreat before the beasts, his fortunate stumble through the gap.

"But you came back."

Vye flushed. He was not going to try to explain that. Instead he said:

"If it went away once, it can again."

Hume did not press the subject of his return. Rather he fastened upon the end of that action with the wounded beast, made Vye go through it verbally a third time.

"There is just this," he said when the other was done. "When you fell you were not thinking of the barrier at all—and your wits were working again. You had come out of the daze we both had."

Vye tried to remember, decided that the Hunter was correct. He had been trying to elude the charge of the beast, only, fear and that desperate desire had occupied his mind at that moment. But what did that signify?

To test just what he did not know, he crawled now to Hume's side, put up his own hand to the space where the plasta-flesh palm slid back and forth on nothingness. But he almost fell on his face, forward into the gap. Where he had been expecting the resistance of the unseen curtain there had been nothing at all! He turned to Hume with the expression of a man who had been stunned by an unexpected blow.

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