httpvh://www.youtube.com/watch?v=6mQJwZERJXQ

Merlin continues with the sixth episode of Series 3 entitled The Changeling.

Arthur is pressured into an arranged marriage with a visiting princess, Elena, as the fantasy drama continues. Yet Merlin has reservations when he discovers Elena may not be exactly who she claims to be.While trying to uncover Elena’s dark secret, Merlin learns that Elena’s nanny is a Pixie. But who is she working for? And what do they have to gain from her marriage to Arthur – the heir to the throne of Camelot? Can Merlin get to the bottom of this mystery before Arthur makes the biggest mistake of his life?

Didn’t they already do this story in Series 2 episode, Sweet Dreams?

The Changeling airs Saturday 16 October at 7.45pm on BBC1.