With a cunning and activity utterly new to him, he glided away, like a snake; downward over crags and boulders, he knew not how long or how far; all he knew was, that he was going down, down, down, into a dim abyss.  There was just light enough to discern the upper surface of a rock within arm’s length; beyond that all was blank.  He seemed to be hours descending; to be going down miles after miles:  and still he reached no level spot.  The mountain-side was too steep for him to stand upright, except at moments.  It seemed one uniform quarry of smooth broken slate, slipping down for ever beneath his feet.—­Whither?  He grew giddy, and more giddy; and a horrible fantastic notion seized him, that he had lost his way; that somehow, the precipice had no bottom, no end at all; that he was going down some infinite abyss, into the very depths of the earth, and the molten roots of the mountains, never to reascend.  He stopped, trembling, only to slide down again; terrified, he tried to struggle upward:  but the shale gave way beneath his feet, and go he must.

What was that noise above his head?  A falling stone?  Were his enemies in pursuit?  Down to the depth of hell rather than that they should take him!  He drove his heels into the slippery shale, and rushed forward blindly, springing, slipping, falling, rolling, till he stopped breathless on a jutting slab.  And lo! below him, through the thin pearly veil of cloud, a dim world of dark cliffs, blue lakes, grey mountains with their dark heads wrapped in cloud, and the straight vale of Nant Francon, magnified in mist, till it seemed to stretch for hundreds of leagues towards the rosy north-east dawning and the shining sea.

With a wild shout he hurried onward.  In five minutes he was clear of the cloud.  He reached the foot of that enormous slope, and hurried over rocky ways, till he stopped at the top of a precipice, full six hundred feet above the lonely tarn of Idwal.

Never mind.  He knew where he was now; he knew that there was a passage somewhere, for he had once seen one from below.  He found it, and almost ran along the boggy shore of Idwal, looking back every now and then at the black wall of the Twll du, in dread lest he should see two moving specks in hot pursuit.

And now he had gained the shore of Ogwen, and the broad coach-road; and down it he strode, running at times, past the roaring cataract, past the enormous cliffs of the Carnedds, past Tin-y-maes, where nothing was stirring but a barking dog; on through the sleeping streets of Bethesda, past the black stairs of the Penrhyn quarry.  The huge clicking ant-heap was silent now, save for the roar of Ogwen, as he swirled and bubbled down, rich coffee-brown from last night’s rain.