Pulchra Arcanum

During the time Merlin was training the great King Arthur, Merlin had a secret. One he's hid for centuries. One which is coming to the surface now. This beautiful secret, this Pulchrum Arcanum, has a name. Her name is Megara; Merlin calls her Meggy.
She's the most powerful woman in the world.
And she finds out it's all a lie.
And then there's blood.
Lots of blood.