Into its silent depths, fascinated by the desolation surrounding him, Raoul gazed intently. He would revive the old ceremony. He would bring an offering to this hidden God--an offering bearing a menace, a demand for the treasure that he felt already in his grasp. He seized a stone from the many that were strewn at his feet. It was smooth, worn by the streams through which it had chafed its way hither; he paused as he weighed it thoughtfully in his outstretched hand. Then he threw it high in air, over the center of the pool. The sound of the falling missile plunging through the waters echoed sullenly along the towering walls of granite. The weird effect delighted him, and again and again he cast stones into the water, dislodging some of the more unwieldy rocks from their resting-places and watching them bound and ricochet, with a thunderous noise, down the precipice after the others. In the midst of this fantastic play he was arrested by the cry of a human voice. High, clear and sibilant it came; a word of command, as it seemed, out of the empty space above: "Silence!" He thought it might be the rustle of the wind that had just sprung up and was stirring the gnarled branches of the trees fringing the brow of the hill upon whose precipitous slope he was standing. Carefully he scanned the rocky pinnacles rising on either side of him. If it was not the wind, the invisible being whose voice he had heard might be hidden in one of the many clefts that furrowed the face of the hill behind him. Again he heard the command. Silvery, unmistakably human; the peremptory voice came from some one near at hand, a few hundred yards, it might be, from where he stood: "Silence!" The tall, slim figure of a woman, clad in flowing white robe, with dazzling arm stretched downward, flashed in sharp outline against the dark hillside. She stood just above him, on a projecting shelf of rock. Her eyes, calm and stern, were not turned toward Raoul, but fixed intently on the lake, as if beholding--or expecting to behold--something there that was hidden from all others. Involuntarily Raoul bent his head to this singular apparition, scarcely knowing whether it was a creature of his imagination, conjured out of the strange fancies awakened by the lonely scene, or a real woman, statuesque, beautiful. Why was she here? Whence had she come? How address her? Vague questions crowded upon him, giving place finally to the conviction that he was an intruder and had unwittingly offended one whose rights here were supreme. And then he yielded to a feeling of shame at being caught in senseless boy's play. "Pardon, Senorita," he murmured lamely. "Ah," she sighed, a trace of irony in her voice; "it is I, a stranger here, who must ask pardon for daring to interrupt you." "Again--pardon," he said, moved by the seriousness, the bitterness in her tone. "Surely, you are not a stranger to Guatavita, to Bogota?" he added, not concealing his astonishment.