Crystal Cave By Mary Stewart. Book one of the Arthurian saga introduces you to the bastard son of a Welsh princess, Myriddn Emrys--or as he would later be known, Merlin. He leads a perilous childhood, haunted by portents and visions. But destiny has great plans for this no-man's-son, taking him from prophesying before the High King Vortigern to the crowning of Uther Pendragon and the conception of Arthur--king for once and always.