We were now amid scenery of the same desolate type that had so impressed me the day of my arrival. Gaunt, barren hills, wild, uncultivated levels, sombre valleys, inhabited only by grotesque enigmatical shadows that came from Heaven knows where, and hemmed us in on all sides. A large quarry, half full of water and partly overgrown with brambles, riveted my attention, and as I gazed fixedly at it I saw, or fancied I saw, the shape of something large and white--vividly white--rise from the bottom. The glimpse I caught of it was, however, only momentary, for we were moving along at a great pace, and I had hardly seen the last of it before the quarry was left behind and we were descending a long and gradual declivity. There was but little wind, but the cold was benumbing; neither of us spoke, and the silence was unbroken save by the monotonous patter, patter of the horse's hoofs on the hard road. We were, I should say, about half-way down the hill, when away in our rear, from the direction of the quarry, came a loud protracted neigh. I at once looked round, and saw standing on the crest of the eminence we had just quitted, and most vividly outlined against the enveloping darkness, a gigantic horse, white and luminous. At that moment our own mare took fright; we were abruptly swung forward, and, had I not--mindful of the Colonel's warning--been "sitting tight," I should undoubtedly have been thrown out. We dashed downhill at a terrific rate, our mare mad with terror, and on peering over my shoulder I saw, to my horror, the white steed tearing along not fifty yards behind us. I was now able to get a vivid impression of the monstrous beast. Although the night was dark, a strong, lurid glow, which seemed to emanate from all over it, enabled me to see distinctly its broad, muscular breast; its panting, steaming flanks; its long, graceful legs with their hairy fetlocks and shoeless, shining hoofs; its powerful but arched back; its lofty, colossal head with waving forelock and broad, massive forehead; its snorting nostrils; its distended, foaming jaws; its huge, glistening teeth; and its lips, wreathed in a savage grin. On and on it raced, its strides prodigious, its mighty mane rising and falling, and blowing all around it in unrestrained confusion. A slip--a single slip, and we should be entirely at its mercy. Our own horse was now out of control. A series of violent plunges, which nearly succeeded in unseating me, had enabled her to get the check of the bit between her teeth so as to render it utterly useless; and she had then started off at a speed I can only liken to flying. Fortunately we were now on a more or less level ground, and the road, every inch of which our horse knew, was smooth and broad.