This is the legend of the Fey Nimue (The Lady of the Lake), who is tasked by her mother Lenore to deliver the Sword of Power (Excalibur) to her father Merlin.

Her greatest enemy is the Christian Church, whose leader, Pope Abel, has sent the zealot Father Carden and his army of warrior monks, The Red Paladin, to cleanse the world of the Fey people and their magic. Assisted by the Weeping Monk (Lancelot), a misguided Fey who has turned against his own people, this holy army mercilessly attack and slaughter the Feys - men, women and children - and anyone who helps them.

Nimue manages to escape when the Paladins reach her village. Others are not so fortunate; her friend Pym is captured.

At Hawksbridge, Nimue meets the mercenary Arthur, who steals the Sword of Power.

She hides in an abbey, calling herself Sister Alice. There she spies on Father Carden, but she has to flee when her true identity is revealed by the treacherous Sister Iris. Another nun, Sister Igraine (Arthur's sister Morgana) helps her escape.

The abbey is burned to the ground and Morgana's lover Sister Celia dies in the fire.

Nimue finds Arthur in Gramaire and asks for the stolen sword. He tells her that the Paladins have taken the Sword of Power from him. Fortunately they are not far away and after a short fight, she regains possession of the sword.

She sends a note to Merlin, who is about to be executed by the tyrannical King Uther. This gets him a temporary reprieve, as the king, a complicit ally of the Paladins, wants the Sword of Power for himself. Merlin agrees to help him in return for his life.

Pym is still alive and is rescued by the Viking Dof.

Nimue, Arthur and Morgana are staying with the Fey' resistance in the woods at Nemos. Sister Iris is also there, intent on killing Nimue and in so doing be allowed to join the Paladins.

Meanwhile love has blossomed between Nimue and Arthur.

Soon other Feys arrive, including Squirrel (Percival) and The Green Knight (Gawain).

Accompanied by Morgana and Kaze, Nimue leaves to meet her father.

In a flashback it is shown how Merlin, King Uther's advisor, is found by Lenore. She removes the Sword of Power lodged in his chest. Lenore and Merlin make love, but shortly afterwards they quarrel and he departs when he discovers that he has lost his powers.

Nimue is disappointed when she finds out what her father's true intentions are: to destroy the Sword of Power. Then Uther's soldiers appear and she flees with her companions.

The Weeping Monk and the Paladins attack the Fey' resistance at the mill. Arthur and Gawain put up a valiant fight.

Finally they are rescued by Nimue, who uses the Sword of Power to defeat the Paladins.

Gawain appoints Nimue as the new leader of the Fey' resistance: the Fey Queen. She succeeds in retaking Gramaire from the Red Paladin, and reunites with Pym.

Alliances are formed between Merlin and Cumber the Ice King, and Father Carden with King Uther and his mother, Lady Lunette.

The Red Paladin and Uther's army march towards Gramaire and besiege the castle.

The Green Knight is captured by the Weeping Monk and brought to the Red Paladin Camp, where he is tortured by Brother Salt. Squirrel tries to free him, but is easily subdued.

In Gramaire there is fighting between the Fey and the others. Iris is adding to the distrust by killing Feys.

Nimue gives Morgana the Sword of Power for safekeping.

Then she decides to surrender and accepts Uther's offer to leave with the Feys on ships.

Something strange is happening to Morgana. She has been touched by the Cailleach - in the form of a spider - and this has given her unnatural sight. She walks into the woods where she sees her dead lover Celia.

King Uther discovers to his horror that he is not of royal blood, but the son of a local peasant woman. Lady Lunette's real son died at birth and desperate for a heir, she had bought him from his biological mother Sylvia. When he goes in search for Sylvia, he learns that she has been poisoned. Uther takes his revenge by doing the same, using poison to kill Lady Lunette.

The Weeping Monk redeems himself and saves Squirrel, but it is too late for the Green Knight. Gawain is dead. Will he be resurrected by Nimue?

While waiting at the harbour, Arthur is attacked by Cumber and his men. When all seems lost, he is rescued by the Vikings, led by Red Spear (Guinevere).

The king takes Nimue prisoner and she is brought before Father Carden for her execution. However, he is distracted by the Widow with Morgana's face, and Nimue swiftly kills him with the Sword of Power.

Nimue leave the camp with Merlin and Morgana, but she cannot escape her fate. Iris shoots Nimue in her chest with several arrows and she falls in the water.

Merlin grabs the Sword of Power and stops the advancing Paladins. Then he disappears with Morgana in his arms.

Continued in season two?