The two kept so near that they could have reached each other by simply extending the hand.

They had no more than fairly started on their withdrawal from the spot, when Johnston touched the arm of his friend, who instantly halted to learn the cause.

"I believe some of 'em are following us," said Johnston.

Fred listened, but his straining ear could detect nothing to warrant such an alarming conclusion, and he so stated.

The sailor became convinced that possibly he was mistaken. There is no law governing noises at night, and it might be that he had misjudged the rustling of a branch or possibly the stealthy footsteps of some wild animal.

Not entirely convinced, however, that his companion was mistaken, Fred once more resumed the advance, trying to perform the difficult task of giving as much attention to the rear as the front.

If the savages suspected the presence of others, they would be likely to tread so lightly that their footfalls could not be heard; but inasmuch as neither of the whites could believe they had even the most shadowy knowledge of them, they relied more on hearing than sight.

Suddenly Fred started and almost uttered an exclamation. In his nervous, apprehensive state, he was sure that one of their dusky foes had leaped from the side of the path and was crouching in front.

He drew his pistol and waited for the a.s.sault, which he was confident would come the next moment; but the seconds pa.s.sed and all remained profoundly still.

With his weapon ready for instant use, he advanced a pace or two, touching the sailor as a command for him to remain motionless; but the chivalrous fellow would not obey, and was close behind him, when he stooped down and placed his hand on a piece of decayed limb that had fallen into the path.

"What a mistake," muttered Fred, with a sigh, as he shoved it aside with his foot, explaining its nature to the wondering Johnston.

But it was only simple prudence to maintain unceasing vigilance, and he did not permit the error to lessen his watchfulness. It was rather the reverse.

But the explorers were threading their way through a labyrinth of peril, the like of which they had never encountered before.

Fred had not gone a hundred yards further, when his companion once more caught his arm, and he turned about as before to learn the cause.

"What have you heard?" he asked, with his mouth almost against the ear of the other.

"There are some of 'em behind us, certain sure!"

"How do you know there are more than one?"

"By the sound--there!"

The amazement of the two may be understood, when they not only detected the sound of footfalls, but discovered that instead of being at the rear as both thought, they were in front!

A party of natives were approaching from the Xingu, and the keener hearing of Johnston first discovered them.

The whites had stopped near a spot where a few rays of moonlight fell upon the trail, giving them a faint but needed view of the direction from which the danger threatened.

Neither spoke again, but with the utmost care and noiselessness, they stepped aside from the path and crouched among the undergrowth.

They had barely time to ensconce themselves in their new position, when the footfalls sounded more distinctly than before, and something in the nature of an exclamation was heard from one of the approaching savages.

It sounded more like the grunt of a pig than anything the listeners could call to mind, and Ashman feared it was notice of one warrior to his companions that he had discovered something amiss.

But if such were the fact, the natives would have stopped, while the cat-like steps were more audible than before, though the wonder to the watchers was that the parties continued invisible.

The eyes of both remained fixed on the faintly illuminated s.p.a.ce, where they expected to catch sight of them, but the straining gaze failed to detect the most shadowy form.

Ashman was just beginning to suspect some strange mistake had been made, when he suddenly saw the form of a tall savage with bushy head and a javelin in his hand, glide like a shadow into the darkness in front. A moment after, a second followed, then a third, fourth and fifth, the last carrying a long-bow, and all plainly seen by the whites at the side of the trail.

A few minutes later, Fred once more took the advance, reflecting that they were as likely to meet more of the natives as to have them overtake them.

The mystery was where they had come from in the first place. They could not have entered the trail at the camp where Ashman and Johnston had started on their little exploring enterprise. It looked as though they were hiding among the trees at the time the canoe approached the land, and may have followed the explorers soon after they started along the path with the purpose of cutting off their retreat. If such should prove to be the case, Fred felt that not only he and his companion were in danger, but all the rest were liable to be attacked by these natives, who, as has been stated, were the most athletic that had been encountered since leaving the Amazon.

"Fred," whispered the sailor a little later, "they've turned back and are following us again."

"Are you sure of it?"

"There's no mistake about it."

Fred was debating whether they should not turn again from the path, but he reflected that the natives having discovered the trick played on them, would be likely to defeat such a piece of strategy.

Before he could decide upon the best course, Johnston whispered:

"Run! it's the only chance we've got!"

CHAPTER VII

DESPERATE WORK.

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--h.e.l.loa! 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.