Standing in the door of the building, his figure so wrapped in gloom that it was invisible to the fierce Murhapas, Professor Grimcke cautiously peered out upon the multitude that were clamorously seeking the death of himself and comrade.

The horde seemed to be everywhere. They were glaring over the river bank, behind which they could find secure shelter by merely dropping their heads; they were crouching at the corners of the adjacent houses, the king's residence affording screen to fully a score. Not yet fully recovered from their panic, they appeared to be awaiting the leadership of some strong man who held the fire-arms of the explorers in less dread than they.

A form rose upright along the Xingu, at the upper portion of the line of savages. In the full moonlight he was as clearly revealed as if at mid-day.

It was with strange feelings that Professor Grimcke saw that this individual belonged to the same race as himself. He was one of the two white men that had lived for years among the Murhapas and who had instigated the furious assault upon them.

"You have earned your fate," muttered the German, bringing his unerring Winchester once more to his shoulder, and sighting as best he could at the unconscious miscreant, who appeared to be conversing with some one sitting on the ground at his side.

The finger of Grimcke was pressing the trigger when, yielding to an unaccountable impulse, he lowered the weapon. He was impatient with himself that his heart should fail him at the critical moment, but perhaps it was well it was so.

"You and I ought to be friends," he reflected, "and it is not my fault that we are not, however, I cannot shoot you down like a dog, though you deserve it."

The emotion which checked him so unexpectedly, also prevented his renewing fire upon the Murhapas, who were really less guilty than he.

He had decided to await the next demonstration before discharging his gun again.

Jared Long was as vigilant and alert as his friend. It may be doubted whether he would have spared Waggaman, had he been given the opportunity to draw bead on him. He realized too vividly that the two defenders never would have been in this fearful situation but for the machinations of those two men.

It seemed to him that Bippo was curiously quiet. He had not spoken, nor, so far as he could judge, moved since his own return from his brief conference with the Professor.

He pronounced his name in a low voice, but there was no reply. A call in a louder tone also failed of response.

"I wonder whether he was killed?" was the thought which led Long to leave his station at the door, and to set out on a tour of investigation around the room, using his hands and feet to aid him.

He expected every minute to come in contact with the lifeless figure of his helper, whom he supposed to have been pierced by the poisoned weapon of the Murhapa; but when he had passed around the apartment and across it several times, until assured that not a foot of square space had been neglected he awoke to the fact that Bippo was not there.

It was hardly probable that he had entered the front apartment, but he made inquiry of the Professor. The latter replied that he had heard nothing of him; but, since he had a few minutes that could be spared without danger for that purpose, he went through a search similar to that of his friend.

"He is not here," called the Professor, in a guarded undertone.

The surprising conclusion followed that the fellow after all had effected his escape from the building, though how it was done puzzled the two whom he left behind.

Bippo had got away by yielding to one of those sudden inspirations which sometimes come to a person. Hearing the explorers speaking about a stealthy withdrawal by the rear, he decided to anticipate them. Without pausing to debate the matter or ask for permission, he slipped out the rear door and moved rapidly off in a crouching posture.

He must have been seen by numbers of the Murhapas, but was mistaken for one of their own number.

The error cannot be regarded as remarkable, when it is recalled that Bippo bore a strong resemblance to the savages around them. He was dressed the same and carried a spear similar to the missiles used by them. Though he lacked their bushy heads and stature, these were not marked enough to attract notice at a time when the Murhapas knew that several of their number had been defeated in their efforts to enter the structure from the rear.

With his wits sharpened by his danger, Bippo displayed admirable discretion. Showing no undue haste or flurry, he avoided too close acquaintance with the savages, who were so absorbed in the work of securing the destruction of the white men that they paid less attention to such an incident than they would at any other time.

So it was that he edged farther and farther away, until he found himself so close to the woods that he whisked among the trees without any one questioning or trying to check him. He was free at last, and, as if Dame Fortune had decided to take him in charge, he had hardly reached the margin of the Xingu, at a point considerably below the village,............