The expedient to which they had recourse was one which their assailants evidently thought impossible. That the rock upon which Edinburgh Castle stands should have been considered inaccessible by practical mountaineers like the followers of Donald Bane seems curious: but in those days the art of climbing for pleasure had not been discovered, and it had no place in the methods of warfare. It seemed enough to the assailants to hold the gates and the summit of the eastern slopes, where probably there must already have been some clusters of huts or rough half-fortified dwellings descending from the Castle Hill, foreshadowing a Lawnmarket at least if not yet a Canongate. No one would seem to have thought of the possibility of any descent on the other side from that perpendicular rock. But despair sharpens the wits, and no doubt after many miserable consultations a desperate expedient was found. Even now nothing but a goat, or a schoolboy, or perhaps a young private fearful of punishment, could find a way down the wonderful curtain of rock which forms the west side of Edinburgh Castle; and to guide the children and their attendants, a sorrowful little group of mourners, distracted with grief and fear, and Margaret's body in its litter, down those rocks where there was scarcely footing for an alert and experienced climber, must have been one of the most difficult as it was one of the boldest of undertakings. While the rebel host raged on the other side, and any traitor might have brought the enemy round to intercept that slow and painful descent, it was accomplished safely under cover of "a great myst," Heaven, as all thought, helping the forlorn fugitives by that natural shield. Mists are no rare things, as everybody knows, on these heights. Perhaps it was the well-known easterly haar, the veil of salt sea fog which Edinburgh so often wraps round her still, which, blowing up from the mouth of the Firth, enveloped the travellers and hid them in its folds of whiteness, impenetrable by the closest watcher, till they had safely reached the level ground, and stealing down to the Queen's Ferry escaped to loyal Fife and their home in Dunfermline. Needless to say that this mist was a miraculous agency to all the family and servants of the Queen. To us it adds a touch of local colour, the well-known symbol of a familiar scene. Edinburgh was then nothing but a castle upon a rock, and now is one of the fairest and most celebrated of historical cities; but still its perpendicular crags rise inaccessible against the setting sun, and still the white mist comes sweeping up from the sea.