Merlin must be more alert than ever if he is to protect Prince Arthur, for his greatest enemy is now within the castle walls.Morgana. Old friends return to the kingdom, and new enemies grow stronger outside the walls of Camelot. Loyalties are tested to the limit as a dangerous game is played for the throne. Now in league with Morgause, Morgana's powers begin to grow and she becomes a deadly enemy within the walls of Camelot, but with Uther and the kingdom blind to her treachery, can Merlin thwart her plans before she can destroy Camelot? Plot Ĭamelot rejoices as the Lady Morgana is found and returned home, however not all is at it seems for Merlin, as he soon learns that Morgana has changed for the worse. BBC officially renewed the show for series 4 on 10 October 2010.

The series was notable for the change in character of Morgana from the sympathetic heroine in the first two series to the villain in series 3, keeping with the historical concept of Morgana as Merlin's nemesis in the legends of King Arthur.

Series 3 introduced the format of a two-part opener and two-part finale, this format was retained for Series 4 and Series 5. The series three premiere was watched by 6.49 million viewers. John Hurt took his previous role as the voice of the Great Dragon but was no longer one of the regular cast (though he continued to provide the opening narration for the series). Series three regular cast members include Colin Morgan, Bradley James, Katie McGrath, Angel Coulby, Anthony Head, and Richard Wilson, as well as Emilia Fox joining the regular cast. The third series of Merlin began on 11 September 2010.

Merlin season 3 episode 4 full episode