Merlin - Series 1 - The Gates of Avalon

Arthur's chivalry lands him in trouble when he jumps to the rescue of a damsel in distress, Sophia, and her elderly father Aulfric. Back in Camelot, Sophia uses more than just her feminine charms to take control of Arthur's heart. This strange behaviour doesn't go unnoticed by Merlin, but can he work out who the mysterious pair are, and what they want with Arthur?