The darkness lowered so heavily upon the black river and the encircling jungle that Tarzan, even with eyes accustomed to much use after dark, could make out nothing a few yards from him. His idea was to search the shore that night for signs of the Russian and the woman who he was certain must have preceded Rokoff down the Ugambi. That the Kincaid or other ship lay at anchor but a hundred yards from him he did not dream, for no light showed on board the steamer. Even as he commenced his search his attention was suddenly attracted by a noise that he had not at first perceived—the stealthy dip of paddles in the water some distance from the shore, and about opposite the point at which he stood. Motionless as a statue he stood listening to the faint sound. Presently it ceased, to be followed by a shuffling noise that the ape-man’s trained ears could interpret as resulting from but a single cause—the scraping of leather-shod feet upon the rounds of a ship’s monkey-ladder. And yet, as far as he could see, there was no ship there—nor might there be one within a thousand miles. As he stood thus, peering out into the darkness of the cloud-enshrouded night, there came to him from across the water, like a slap in the face, so sudden and unexpected was it, the sharp staccato of an exchange of shots and then the scream of a woman. Wounded though he was, and with the memory of his recent horrible experience still strong upon him, Tarzan of the Apes did not hesitate as the notes of that frightened cry rose shrill and piercing upon the still night air. With a bound he cleared the intervening bush—there was a splash as the water closed about him—and then, with powerful strokes, he swam out into the impenetrable night with no guide save the memory of an illusive cry, and for company the hideous denizens of an equatorial river. The boat that had attracted Jane’s attention as she stood guard upon the deck of the Kincaid had been perceived by Rokoff upon one bank and Mugambi and the horde upon the other. The cries of the Russian had brought the dugout first to him, and then, after a conference, it had been turned toward the Kincaid, but before ever it covered half the distance between the shore and the steamer a rifle had spoken from the latter’s deck and one of the sailors in the bow of the canoe had crumpled and fallen into the water. After that they went more slowly, and presently, when Jane’s rifle had found another member of the party, the canoe withdrew to the shore, where it lay as long as daylight lasted. The savage, snarling pack upon the opposite shore had been directed in their pursuit by the black warrior, Mugambi, chief of the Wagambi. Only he knew which might be foe and which friend of their lost master.