It seemed to be the only course left. Whether it was or not, it was too late to try anything else. That the natives had discovered the explorers was proven by several low, tremulous whistles which at that instant sounded on the night.

It was risky running along the dark trail, even though illuminated here and there by the rays of the moon: but, feeling that the situation was desperate, Ashman broke into a swift lope, with Johnston at his heels, urging him to make haste.

"If they come too close," thought the young man, "we can dodge among the trees again and pick our way back to the river as best we can—helloa! what's that?"

Well might he ask himself the question, for the whizz of something close to his ear left no doubt that one of their pursuers had hurled a poisoned javelin at them.

An instant after he heard a faint but peculiar noise which he could not describe nor identify. Johnston at the same instant uttered a suppressed exclamation, not intended for his ears, and he called out in a recklessly loud voice,

"Into the woods, quick!"

Ashman did not hesitate, but darted to his right, halting after a couple of steps, through fear of betraying himself.

"Where are you?" asked Johnston, speaking more guardedly.

His groping hand touched Ashman, who seized it and silently drew him forward, neither speaking again.

Even in that trying moment, the younger was impressed by the singularity of his friend's actions, though there was no opportunity to ask an explanation.

The savages could be plainly heard, as they hurried past, evidently believing they would overtake the fugitives the next minute and certain of locating them, wherever they might be.

Sure enough, they had not gone fifty feet, when they detected the trick and turned about to catch the whites before they could steal any distance from the trail.

"We must leave," said Ashman; "we are too close to the path, and they are sure to find us."

Johnston made no answer, and, instead of following him, sank heavily to the ground, with a groan.

"Great heaven! what is the matter, Aaron?" gasped his friend.

"I'm done for," was the feeble reply; "never mind me: look—out—for—for—good-bye!"

Struck almost dumb by an awful fear, Fred forgot the natives for the time and stooped over his friend. It was as he suspected; the poor fellow had been struck full in the back by one of the poisoned javelins. The exclamation which he uttered at the moment of receiving the wound was that which puzzled Ashman. The sailor had withdrawn the weapon, and the wound bled but little. The young man, however, identified it on the instant.

"Aaron, rouse up!" he called, shaking his shoulder; "fight off your drowsiness!"

He suddenly ceased, for at that moment, he realized that his companion was dead. Thus fearfully did the virus do its work.

Before Ashman, could do more than rally from his shock, a muttered exclamation at his elbow announced that the savages had located him.

"Curse you!" he exclaimed, whipping out his revolver and letting fly in the dark at the point where he knew several of his foes were standing, waiting for a chance to hurl their missiles at him.

A screech announced that the bullet had found its mark, and he followed it with a couple more shots, which inflicted wounds, even if they caused no mortal ones.

The effect of this volley was to throw the natives into consternation and panic. There is nothing go appalling as an unknown peril, and the flashes of fire lighting up the gloom sent them flying toward their village.

The path was open for the young man's escape, but could he leave the body of his friend behind?

Alas! it was that all he could do, and unless that were done within the next few minutes, it would be too late.

Stooping over, he grasped the shoulders of the body and drew it further from the path, in the hope that it would remain unnoticed. Then he loosed the Winchester from the death grip, removed the revolver, and stepping back into the trail, started on his sorrowful return to his friends.

"I wish they would follow me," he muttered; glaring into the gloom behind him; "the man they have killed is worth more than the whole tribe of miscreants."

He was in a savage mood, and, despite the fearful danger from the poisoned arrows and spears, he yearned for another chance at the wretches who fought so unfairly.

He held a couple of loaded and repeating Winchesters, with which he could pour the most destructive of volleys among the savages, and he longed for the opportunity; but the profound silence which followed the fierce encounter was so striking that to Fred it all seemed like some horrid vision of sleep.

But he dare not wait. These wretches had come from the direction of the Xingu, and he was apprehensive of trouble at the camp, where the three native attendants had been left. His services might be needed at that very moment.

He did not run, but advanced with the stealth of an American Indian stealing upon an enemy. It seemed to him his senses were strung to a higher pitch than ever before, for he had not walked far, when he became aware that some one was ahead of him, in the path and travelling in the same direction.

As yet he could catch no glimpse of the stranger, but there could be no mistake about the stealthy tread. He was sure, too, that sooner or later the broken rays of moonlight would give him the sight for which he was waiting.

"Yonder is a spot where he will betray himself," he added a moment later, as he observed the faint light ahead.

Instead of following on, Fred paused and laying the rifle of his dead friend on the ground he knelt and sighted his own piece as best he could in the darkness. Where the hunter is placed in such a situation he instinctively feels how to aim his weapon.

He was not kept long waiting. A dark form became dimly outlined in the faint moonlight and an instant later the infuriated Ashman fired.

The rasping screech which followed was enough to curdle one's blood, but the young man only uttered an exclamation of disgust. He had driven a ball through the vitals of a South American cougar, instead of through one of the natives, a score of whom he gladly would have wiped out of existence had he possessed the power.

The shot could not have been better aimed, had the sun been shining. The furious beast dropped in the middle of the path, rolled over on his back, clawed the air for a moment or two, and then became motionless. Had not Ashman been on the lookout when he reached the spot, he would have stumbled over the carcass.

"It is only so much ammunition thrown away," he muttered, again glaring into the gloom behind him, in the hope of catching sight or sound of his pursuers; but they were too thoroughly panic-stricken by the frightful experience a few minutes before to trouble the white man for some time to come.

The dull roar of the rapids grew plainer, and, increasing his pace, he had but to walk a short distance when the clear moonlight, unobstructed by cloud or vegetation, was discerned where the path debouched from the forest.

The feeling that something had gone amiss in the camp during his absence was so strong with Ashman that he slowed his walk and stopped before emerging from the wood. He paused, however, at a point where he had a full view not only of the camp but of the river and dark shore beyond.

The sight which met his gaze was not calculated to soothe his nerves. From some cause Bippo, Pedros and Quincal seemed to have been seized with a panic, hardly less than that produced among their countrymen by the discharge of the firearms of Ashman. They were in the act of shoving the canoe back into the water in such haste that there could be no doubt they intended to flee from some enemy that had driven all thoughts of resistance out of their minds.

"What the mischief are you doing?" shouted the young man, dashing from cover and hurrying down the bank to intercept them before they could get away.