With Princess Mithian (Janet Montgomery) as the perfect bait, Morgana conjures a deception so powerful that the whole of Camelot is taken in - even Merlin himself.
But as the storm clouds gather, will the young warlock see through the lies? Or will Morgana at long last fulfil her dreams of revenge?
Colin Morgan is Merlin, Bradley James is Arthur, Angel Coulby is Gwen, Katie McGrath is Morgana, Richard Wilson is Gaius and John Hurt is the voice of the Great Dragon. Tom Hopper, Rupert Young, Eoin Macken and Adetomiwa Edun return as The Knights of the Round Table. Special guest stars include Janet Montgomery as Princess Mithian, and James Fox as King Rodor.
Saturday 27 October