But he had not crossed half the distance between them when the man uttered an appalling cry, so wild and despairing that it seemed to chill even the hot blood in Clarence's veins, and dashed frenziedly down the cross-road into the interminable plain. Before Clarence could determine if that cry was a signal or an involuntary outburst, it was followed instantly by the sound of frightened and struggling hoofs clattering against the wall of the casa, and a swaying of the shrubbery near the back gate of the patio. Here was his real quarry! Without hesitation he dug his heels into the flanks of his horse and rode furiously towards it. As he approached, a long tremor seemed to pass through the shrubbery, with the retreating sound of horse hoofs. The unseen trespasser had evidently taken the alarm and was fleeing, and Clarence dashed in pursuit. Following the sound, for the shrubbery hid the fugitive from view, he passed the last wall of the casa; but it soon became evident that the unknown had the better horse. The hoof-beats grew fainter and fainter, and at times appeared even to cease, until his own approach started them again, eventually to fade away in the distance. In vain Clarence dug his heels into the flanks of his heavier steed, and regretted his own mustang; and when at last he reached the edge of the thicket he had lost both sight and sound of the fugitive. The descent to the lower terrace lay before him empty and desolate. The man had escaped! He turned slowly back with baffled anger and vindictiveness. However, he had prevented something, although he knew not what. The principal had got away, but he had identified his confederate, and for the first time held a clue to his mysterious visitant. There was no use to alarm the household, which did not seem to have been disturbed. The trespassers were far away by this time, and the attempt would hardly be repeated that night. He made his way quietly back to the corral, let loose his horse, and regained the casa unobserved. He unlocked the arched door in the wall, reentered the darkened passage, stopped a moment to open the door of the boudoir, glance at the closely fastened casement, and extinguish the still burning candle, and, relocking the door securely, made his way to his own room. But he could not sleep. The whole incident, over so quickly, had nevertheless impressed him deeply, and yet like a dream. The strange yell of the vacquero still rang in his ears, but with an unearthly and superstitious significance that was even more dreamlike in its meaning. He awakened from a fitful slumber to find the light of morning in the room, and Incarnacion standing by his bedside. The yellow face of the steward was greenish with terror, and his lips were dry. “Get up, Senor Clarencio; get up at once, my master. Strange things have happened. Mother of God protect us!” Clarence rolled to his feet, with the events of the past night struggling back upon his consciousness.