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, when he almost stumbled over pedros, who was waiting and wondering what he ought to do next.

both the professor and his friend were glad that bippo had managed to get away. they liked the fellow, and, even if they must be sacrificed, it was a relief to know that the poor native, who had had such a woful experience since leaving the amazon, now had a fighting chance of escaping from the dreadful region.

besides, as has been shown, the presence of the fellow was more of an incumbrance than a help. but for the delay caused by long's rush to his help, the whites would have made a dash for liberty themselves, though the question of their escape was problematical to the last degree.

precious little ground could the explorers see for extricating themselves from their peril. the murhapas numbered a hundred, all were brave, and the weapons in their hands were dreaded tenfold more than firearms. it seemed miraculous that grimcke and long had not been pierced long before. why did not the murhapas set fire to the building, after the manner of the north american indians?

this was the question which both the defenders had asked themselves several times, but in the case of each the answer was obvious.

the house, it will be recalled, adjoined that of king haffgo, and, although there was no wind blowing, the burning of the less important structure was sure to endanger the other. as a last resort, the white men might be driven out in that way, but not yet.

if the besiegers could persuade themselves to make a united rush, they would be sure to prevail; but, as has been explained, the cost of such an essay was sure to be frightful, and led the murhapas to defer that, also, until assured less risky means would not prevail.

it seemed to our friends that there were scores of schemes which ought to be successful, and, such being the case, it will be understood why they believed their last fight was on, and why they were disposed to show no mercy to their assailants.

the professor was surprised, knowing, as he did, the part taken against them by waggaman and burkhardt, that no reports of firearms had yet been heard among the assailants. it would seem as if something of the kind was required in order that those miscreants should retain their prestige among the people.

now, all these thoughts and many more passed through the minds of the defenders in a tenth of the time it has taken us to put them on paper. it was yet early in the evening, and the crisis in the siege must come before long.

jared long peeped out of the rear entrance. a study of what he saw showed little change in the situation. he was convinced that the next demonstration would be from the front. he, therefore, did not hesitate to leave his post and slip into the next room for a few hasty words with the professor.

"there's no use of staying in here," he said, "for we are sure to be overwhelmed within the next hour."

"i fully agree with you."

"and i can see but one desperate hope."

"what is that?"

"to follow bippo."

"i agree with you again; let us make such a demonstration from the front that we shall be able to draw most of them there; then one of us will make a rush."

"why not both."

"we shall fail; one must keep up the firing while they think both are at it, and then the other can make the attempt."

"very well; let me open here."

"no; we will both do it; you know that this station is mine and as soon as there appears to be a chance, you can make the start."

now, both of the men believed in their hearts that if the desperate scheme could work, that the utmost it could do would be to save one: there could be no earthly chance for the other.

it was characteristic of the chivalrous friendship of each that he had fully determined that that forlorn opportunity should be given to the other.

but they understood their mutual natures too well to waste any words in argument, for neither would yield.

"very well, professor; we'll draw lots."

"i will agree to that."

it was so dark in the room that they could not see each other, nor did either window afford light enough for their purpose.

grimcke glanced out the door. no immediate movement seemed impending, and they moved to the fire-place. the professor kicked some of the ashes aside and a tiny blaze arose, throwing a dull illumination over a few feet of the room.

the professor drew an american coin from his pocket,—one that he had kept ever since entering south america.

"now," said he, placing both hands behind his back, "tell me which contains it."

"the right," said the new englander.

"you have lost," coolly replied the professor, bringing the two hands quickly to the front and opening the palms.

sure enough the coin was in the left, but the sly fellow did not confess that he had deftly changed it after his companion made his guess.