The legend of King Arthur ( Paul Curran ), this time, from the perspective of the King's Wizard, Merlin ( Sam Neill ). Merlin is a creature born of pagan magic, living in a world converting to Christianity. Merlin is beside Arthur as he gains Excalibur, builds Camelot, and is betrayed by his wife, Guinevere (Lena Headey). Merlin and Arthur are menaced by the plots of Morgan Le Fey (Helena Bonham Carter), her son by Arthur, Mordred (Jason Done), and their cohorts. Through it all, Merlin tries to keep Arthur from the destructive path set by fate.