The first ten episodes of the TV series based loosely on Arthurian legend starring Joseph Fiennes and Eva Green. The series begins with the sorcerer Merlin (Fiennes) conniving to place a young Arthur (Jamie Campbell Bower) on the throne. This is to the displeasure of Arthur's half-sister Morgan (Green), upset at being usurped for the throne by her younger brother, not to mention Arthur's countless other enemies, including Morgan's ally King Lot (James Purefoy). As Arthur struggles to stabilise the kingdom and his romantic entanglement with Guinevere (Tamsin Egerton), wife of his bravest knight Leontes (Philip Winchester), the greatest threat to his rule may come from within the family as Morgan turns to dark forces in her bid to gain power...