Arthur is challenged to a duel by a mysterious warrior. Arthur and Merlin then find themselves on a quest on Morgause's behalf. A dark secret is discovered by Arthur that could change Camelot forever.

Gwen takes centre-stage in this week's Merlin when her long-lost brother Elyan is kidnapped by Cenred. With Arthur and Merlin at her side, Gwen rides to the castle of Fyrien to confront the warlord.

So how about that for epic? The penultimate episode of Merlin ended on a dramatic cliffhanger - our hero (Colin Morgan) met his destiny deep within the Crystal Cave, while Arthur (Bradley James) ...