Deep in the heart of the Caucasus mountains a wild storm was gathering. Drear shadows drooped and thickened above the Pass of Dariel, -that terrific gorge which like a mere thread seems to hang between the toppling frost-bound heights above and the black abysmal depths below, -clouds, fringed ominously with lurid green and white, drifted heavily yet swiftly across the jagged peaks where, looming largely out of the mist, the snow-capped crest of Mount Kazbek rose coldly white against the darkness of the threatening sky. Night was approaching, though away to the west a road gash of crimson, a seeming wound in the breast of heaven, showed where the sun had set an hour sinc