Le Morte d'Arthur

S1, E13: Gaius is deeply troubled when a Questing Beast is spotted in Camelot. A creature conjured from the nightmares of a long dead king, not only is its bite fatal but it is feared as an omen of impending doom... Friendship, loyalty and love are all tested to the limit as Merlin is forced to choose between those he loves most in the world. Just how far is the young sorcerer prepared to go to protect his destiny? And what will he have to sacrifice in order to do so?