A year after her husbands sudden death, ceramic artist Tilda Fordwells finally moves into the secluded Welsh cottage that was to be their new home. She hopes that the tranquil surroundings will help ease her grief, and lessen her disturbing visions of Mats death. Instead, the lake in the valley below her cottage seems to spark something dormant in her - a sensitivity, and a power of some sort. Animals are drawn to her, electricity shorts out when shes near, and strangest of all, she sees a new vision a boatful of ancient people approaching her across the water. On this same lake in Celtic times lived Seren, a witch and shaman. She was respected but feared, kept separate from the community for her strange looks. When a vision came to her of the Prince amid a nest of vipers she warned of betrayal from one of his own.