Sitting up, Dane stared wide-eyed into the dark. A handful of glowing coals, guarded by rocks, was the center of their camp. He hunched up to that hardly knowing why he moved. His hands were shaking, his skin damp with sweat no heat produced. Yet, now that he was conscious of the night, the Terran could not remember the nightmare from which he had just awakened, though he was left with a growing apprehension which he could not define. What prowled out there in that dark? Walked the mountain side? Listened, spied and waited?

Dane half started to his feet as a form did move into the dim light of the fire. Tau stood there, regarding him with sober intensity.

"Bad dream?"

The younger man admitted to that with a nod, partly against his will.

"Well, you aren't the only one. Remember any of it?"

With an effort, Dane looked away from the encircling dark. It was as if the fear which had shaken him awake, now embodied, lurked right there.

"No." He rubbed sleep-smarting eyes.

"Neither did I," Tau remarked. "But both of 'em must have been jet-powered."

"I suppose one could expect to have nightmares after yesterday." Dane advanced the logical explanation, yet at the same time something deep inside him denied every word of it. He had known nightmares before; none of them had left this aftertaste. And he wanted no return of sleep tonight. Reaching to the pile of wood he fed the fire as Tau settled down beside him.

"There is something else...." the medic began, and then fell silent. Dane did not press him. The younger man was too busy fighting a growing desire to whirl and aim the fire ray into that darkness, to catch in its withering blast that lurking thing he could feel padded there, biding its time.

Despite his efforts Dane did drowse again before morning, waking unrefreshed, and, to his secret dismay, with no lessening of his odd dislike for the country about them.

Asaki did not suggest that they trail the poachers into the morass of Mygra. Instead the Chief Ranger was eager to press on in the opposite direction, find a way over the range to the preserve where he could assemble a punitive force to deal with the outlaws. So they began an upward climb which took them away from the dank heat of the lowlands, into the parched blaze of the sunbaked ledges above.

The sun was bright, far too bright, and there were few shadows left. Yet Dane, stopping to drink sparingly from his canteen, could not lose that sense of eyes upon him, of being tracked. Rock apes? Cunning as those beasts were, it was against their nature to trail in utter silence, to be able to carry through a long-term project. Lion, perhaps?

He noted that Nymani and Asaki took turns at rear guard today, and that each was alert. Yet, oddly enough, none of them mentioned the uneasiness they must all share.

They had a dry climb, finding no mountain stream to renew their water supply. All being experienced in wilderness travel, they made a mouthful of liquid go a long way. When the party halted slightly before midday, canteens were still half full.

"Haugh!"

They jerked up, hands on weapons. A rock ape, its hideous body clearly seen here, capered, coughed, spat. Asaki fired from the hip and the thing screeched, clawed at its chest where the dark blood spewed out, and raced for them. Nymani cut the beast down and they waited tensely for the attack of the thing's tribe, which should have followed the abortive lunge on the part of their scout. But there was nothing—neither sound nor movement.

What did follow froze them all momentarily. That mangled body began to move again, drew itself together, crawled toward them. Dane knew that it was impossible that the creature could live with such wounds. Yet the beast advanced, its head lolling on its hunched shoulders so that the eyes were turned blindly up to the full glare of the sun, while it crawled to reach the man it could not see.

"Demon!" Nymani dropped his needler, shrank back against the rocks.

As the thing advanced, before their eyes the impossible happened. Those gaping wounds closed, the head straightened on the almost invisible neck, the eyes glared once more with life, and slaver dripped from the swine snout.

Jellico caught up the needler Nymani had dropped. With a coolness Dane envied, the captain shot. And for the second time the rock ape collapsed, torn to ribbons.

Nymani screamed, and Dane tried to choke back his own cry of horrified protest. The dead thing put on life for the second time, crawled, got somehow to its feet, healed itself, and came on. Asaki, his face greenish-pale, stepped out stiffly as if each step he took was forced by torture. He had dropped his needler. Now he caught up a rock as large as his own head, raised it high with arms on which the muscles stood out like ropes. He hurled the stone, and Dane heard as well as saw the missile go home. The rock ape fell for the third time.

When one of those taloned paws began to move again, Nymani broke. He ran, his screams echoing thinly in the air, as the thing lurched up, the gory mess of its head weaving about. If his feet would have obeyed him, Dane might have followed the Khatkan. As it was, he drew his ray and aimed it at that shambling thing. Tau struck up the barrel.

The medic's face was livid; there was the same horror in his eyes. But he moved out to front that monster.

A spot of shadow coalesced on the ground, deepened in hue, took on substance. Crouched low facing the rock ape, its haunches quivering for a deadly spring, narrowed green eyes holding on its prey, was a black leopard.

The tiny forward and backward movements of its body steadied, and it arched through the air, brought down the ape. A pitting, snarling tangle rolled across the slope—and was gone!

Asaki's hands shook as he drew them down his sweating face. Jellico readied a second clip in the needler mechanically. But Tau was swaying so that Dane leaped to take the shock of the other's weight as he collapsed. Only for a moment did the medic hang so, then he struggled to stand erect.

"Magic?" Jellico's voice, as controlled as ever, broke the silence.

"Mass hallucination," Tau corrected him. "Very strong."

"How!" Asaki swallowed and began again. "How was it done?"

The medic shook his head. "Not by the usual methods, that is certain. And it worked on us—on me—when we weren't conditioned. I don't understand that!"

Dane could hardly believe it yet. He watched Jellico stride to where the tangle of struggling beasts had rolled, saw him examine bare ground on which no trace of the fight remained. They must accept Tau's explanation; it was the only sane one.

Asaki's features were suddenly convulsed with a rage so stark that Dane realized how much a veneer was the painfully built civilization of Khatka.

"Lumbrilo!" The Chief Ranger made of that name a curse. Then with a visible effort he controlled his emotions and came to Tau, looming over the slighter medic almost menacingly.

"How?" he demanded for the second time.

"I don't know."

"He will try again?"

"Not the same perhaps—"

But Asaki had already grasped the situation, was looking ahead.

"We shall not know," he breathed, "what is real, what is not."

"There is also this," Tau warned. "The unreal can kill the believer just as quickly as the real!"

"That I know also. It has happened too many times lately. If we could only find out how! Here are no drums, no singing—none of the tricks to tangle a man's mind that he usually uses to summon his demons. So without Lumbrilo, without his witch tools, how does he make us see what is not?"

"That we must discover and speedily, sir. Or else we shall be lost among the unreal and the real."

"You also have the power. You can save us!" Asaki protested.

Tau drew his arm across his face. Very little of the normal color had returned to his thin, mobile features. He still leaned against Dane's supporting arm.

"A man can do only so much, sir. To battle Lumbrilo on his own ground is exhausting and I can not fight so very often."

"But will he not also be exhausted?"

"I wonder...." Tau gazed beyond the Khatkan to the barren ground where leopard and rock ape had ceased to be. "This magic is a tricky thing, sir. It builds and feeds upon a man's own imagination and inner fears. Lumbrilo, having triggered ours, need not strive at all, but let us ourselves raise that which will attack us."

"Drugs?" demanded Jellico.

Tau gave a start sufficient to take him out of Dane's loose hold. His hand went to the packet of aid supplies which was his own care, his eyes round with wonder and then shrewdly alert.

"Captain, we disinfected those thorn punctures of yours. Thorson, your foot salve.... But, no, I didn't use anything—"

"You forget, Craig, we all had scratches after that fight with the apes."

Tau sat down on the ground. With feverish haste he unsealed his medical supplies, laid out some containers. Then delicately he opened each, examined its contents closely by eye, by smell, and two by taste. When he was done he shook his head.

"If these have been in any way meddled with, I would need laboratory analysis to detect it. And I don't believe that Lumbrilo could hide traces of his work so cleverly. Or has he been off-planet? Had much to do with off-worlders?" he asked the Chief Ranger.

"By the nature of his position he is forbidden to space voyage, to have any close relationship with any off-worlder. I do not think, medic, he would choose your healing substances for his mischief. There would only be chance to aid him then in producing the effects he wants. Though there is often call for first aid in travel, he could not be certain you would use any of your drugs on this trip to the preserve."

"And Lumbrilo was certain. He threatened something such as this," Jellico reminded them.

"So it would be something which we would all use, which we had to depend upon...."

"The water!" Dane had been holding his own canteen ready to drink. But as that possible explanation dawned in his mind, he smelled instead of tasted the liquid sloshing inside. There was no odor he could detect. But he remembered Tau commenting on the powdered purifier pills at their first camp.

"That's it!" Tau dug further into his kit, brought out the vial of white powder with its grainy lumps. Pouring a little into the palm of his hand he smelled it, touched it with the tip of his tongue. "Purifier and something else," he reported. "It could be one of half a dozen drugs, or some native stuff from here which we've never classified."

"True. There are drugs we have found here." Asaki scowled down at the green mat of jungle. "So our water is poisoned?"

"Do you always purify it?" Tau asked the Chief Ranger. "Surely during the centuries since your ancestors landed on Khatka you must have adapted to native water. You couldn't have lived otherwise. We must use the purifier, but must you?"

"There is water and water." Asaki shook his own canteen, his scowl growing fiercer as the gurgle from its depths was heard. "From springs on the other side of the mountains we drink—yes. But over here, this close to the Mygra swamps, we have not done so. We may have to chance it."

"Do you think we are literally poisoned?" Jellico bored directly to the heart of their private fears.

"None of us have been drinking too heavily," Tau observed thoughtfully. "And I don't believe Lumbrilo had outright killing in mind. How long the effect will last I have no way of telling."

"If we saw one rock ape," Dane wondered, "why didn't we see others? And why here and now?"

"That!" Tau pointed ahead on the trail Asaki had picked for their ascent. For a long moment Dane could see nothing of any interest there and then he located it—a finger of rock. It did not point directly skyward this time, in fact it slanted so that its tip indicated their back trail. Yet in outline the spire was very similar to that outcrop from which the real rock ape had charged them the day before.

Asaki exclaimed in his own tongue and slapped his hand hard against the stock of the needler.

"We saw that and so again we saw an ape also! Had earlier we been charged by graz or jumped by a lion in such a place, then again we would have been faced by graz or lion here!"

Captain Jellico gave a bark of laughter colored only by the most sardonic humor. "Clever enough. He merely leaves it to us to select our own ghost and then repeat the performance in the next proper setting. I wonder how many rocks shaped like that one there are in these mountains? And how long will a rock ape continue to pop out from behind each one we do find?"

"Who knows? But as long as we drink this water we're going to continue to have trouble; I feel safe in promising that," Tau replied. He put the vial of doctored purifier into a separate pocket of his medical kit. "It may be a problem of how long we can go without water."

"Perhaps," Asaki said softly. "Only not all the water on Khatka comes running in streams."

"Fruit?" Tau asked.

"No, trees. Lumbrilo is not a hunter, nor could he be certain when and where his magic would go to work. Unless the flitter was deliberately sabotaged, he was planning for us to use our canteens in the preserve. That is lion country and there are long distances between springs. This is jungle below us and there is a source there I think we can safely tap. But first I must find Nymani and prove to him that this is truly deviltry of a sort, but not demon inspired."

He was gone, running lightly down-slope in the direction his hunter had taken, and Dane spoke to Captain Jellico.

"What's this about water in trees, sir?"

"There is a species of tree here, not too common, with a thickened trunk. It stores water during the rainy season to live on in the hot months. Since we are in the transition period between rains, we could tap it—if we locate one of the trees. How about that, Tau? Dare we drink that without a purifier?"

"Probably a choice of two evils, sir. But we have had our preventive shots. Personally, I'd rather battle disease than take a chance on a mind-twisting drug. You can go without water just so long...."

"I'd like to have a little talk with Lumbrilo," remarked Jellico, the mildness in his voice very deceptive.

"I'm going to have a little talk with Lumbrilo, if and when we see him again!" promised Tau.

"What are our chances, sir?" Dane asked. He screwed the cap back on his canteen, his mouth feeling twice as dry since he knew he dared not drink.

"Well, we've faced gambles before." Tau sealed the medical kit. "I'd like to see one of those trees before sundown. And I don't want to face another pointed rock today!"

"Why the leopard?" asked Jellico reflectively. "Another case of using flame to fight fire? But Lumbrilo wasn't among those present to be impressed."

Tau rubbed his hand across his forehead. "I don't really know, sir. Maybe I could have made the ape vanish without a counter projection, but I don't think so. With these hallucinations it is better to battle one vision against another for the benefit of those involved. And I can't even tell you why I selected a leopard—it just flashed into mind as about the fastest and most deadly animal fighter I could recall at that moment."

"You'd better work out a good list of such fighters." Jellico's grim humor showed again. "I can supply a few if you need them. Not that I don't share your hope we won't see any more trigger rocks. Here comes Asaki with his wandering boy."

The Chief Ranger was half-leading, half-supporting his hunter, and Nymani seemed only half-conscious. Tau got to his feet and hurried to meet them. It would appear that their search for the water tree would be delayed.

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