In Ancient Wales, Gwion Bach, a simple woodsman, becomes enchanted by the fey beauty Creirwy during a brush with the Sons of the Long Knives. He earns Creirwy's trust, and tthat of her mother, the goddess Keridwen, and is offered an apprenticeship at their castell in Llyn Tegid. As Gwion discovers an enchanting new world of magic, the goddess is busy brewing a potion of prophetic insight and esoteric wisdom, destined for her monstrous son. However, an ill-timed accident provides an unexpected result. What transpires is an unforgettable shapeshifting battle that will spark rebellion and threaten to bring the downfall of all the kingdoms of Cymru.
