On the plain of Camlann, two armies meet for the last battle. Arthur faces Mordred, Excalibur returns to the lake, and a boat crosses the mist toward Avalon. The end of the Arthurian legends — and the promise of the once and future king.

Arthur's half-sister, Merlin's student, keeper of the old magic. Morgana le Fay was both Camelot's ally and its enemy, and her story asks a difficult question: is anyone ever only good or only bad?