to the top john kearns led us now , to the very summit of the abyss , over deep drops and shadow-stuffed ravines , up craggy edifices where every handhold was precarious and every step fraught with peril , around heaps of shattered stone and deep pools of crystalline water reflecting back the empty sky , along terraced ledges thrust out like balconies overlooking the diksam plateau , an empty , featureless landscape two thousand feet beneath us .