Grace had ventured out to the extreme limit of the rocky cliff, and with straining eyes was trying to peer beyond the snow fields, when the treacherous ledge on which she was standing began to give way. In an instant Philip was at her side and had caught her hand, but at the same moment a large rock of the ledge dropped from beneath her feet, and left her with no support but his grasp. The sudden shock loosened also the insecure granite on which Philip stood. Before he could gain secure foothold it also trembled, tottered, slipped, and then fell, carrying Philip and Grace with it. Luckily this immense mass of stone and ice got fairly away before them, and ploughed down the steep bank of the cliff, breaking off the projecting rocks and protuberances, and cutting a clean, though almost perpendicular, path down the mountain side. Even in falling Philip had presence of mind enough to forbear clutching at the crumbling ledge, and so precipitating the rock that might crush them. Before he lost his senses he remembered tightening his grip of Grace's arm, and drawing her face and head forward to his breast, and even in his unconsciousness it seemed that he instinctively guided her into the smooth passage or "shoot" made by the plunging rock below them; and even then he was half conscious of dashing into sudden material darkness and out again into light, and of the crashing and crackling of branches around him, and even the brushing of the stiff pine needles against his face and limbs. Then he felt himself stopped, and then, and then only, everything whirled confusedly by him, and his brain seemed to partake of the motion, and then--the relief of utter blankness and oblivion. When he regained his senses, it was with a burning heat in his throat, and the sensation of strangling. When he opened his eyes he saw Grace bending over him, pale and anxious, and chafing his hands and temples with snow. There was a spot of blood upon her round cheek. "You are hurt, Grace!" were the first words that Philip gasped. "No!--dear, brave Philip--but only so thankful and happy for your escape." Yet, at the same moment the colour faded from her cheek, and even the sun-kissed line of her upper lip grew bloodless, as she leaned back against a tree. But Philip did not see her. His eyes were rapidly taking in his strange surroundings. He was lying among the broken fragments of pine branches and the débris of the cliff above. In his ears was the sound of hurrying water, and before him, scarce a hundred feet, a rushing river! He looked up; the red glow of sunset was streaming through the broken limbs and shattered branches of the snow-thatched roof that he had broken through in his descent. Here and there along the river the same light was penetrating the interstices and openings of this strange vault that arched above this sunless stream.