Andrew Davies' BAFTA-nominated eight-part drama brings romance, treachery and magical adventure via a host of legendary characters: wily old Merlin, brave Sir Lancelot, King Arthur himself, ruler of all Britain and master of the Knights of the Round Table, the beguiling Queen Guinevere and her nemesis Morgan le Fay. Dark Ages wizard Merlin (Robert Eddison), weary of the barbarism around him, creates a new order of enlightenment and justice with a youthful Arthur (Andrew Burt) at its head. Merlin presents Arthur with the magic sword Excalibur to help him defeat the nobles who oppose his rule. But Arthur must also beware his half-sister Morgan (Maureen O'Brien), a sorceress who has sworn to kill him to avenge her father's death. As Morgan intensifies her campaign, she uses magic to draw Lancelot (David Robb) and Guinevere (Felicity Dean) into a passionate affair. But it is the still more traitorous Mordred (Steve Hodson) who will fatally halt Arthur's rule.