Merlin - The Castle Of Fyrien

Morgause's ally, Cenred, kidnaps Gwen from Camelot only to show her he has also kidnapped her brother, Elyan.  Cenred threatens to kill her brother if she does not go back to Camelot and bring Arthur to him.  Of course Arthur will do anything for her, just as Morgana has predicted.  She even volunteers to come along, revealing the secret entrance to her sister that the little band is to use to rescue Elyan.  Will they rescue Elyan or will someone not return to Camelot?