A year on from the loss of Lord Pelagius Hunt of Mirecoombe, new Keeper Nancy Bligh is still struggling. She can banish the spirits and keep peace between the spriggans and piskies, but every time Nancy sleeps, she dreams of drowning. She is haunted by loss, and by whispers from all around of The Mother, and Nancy's witchcraft. As the only witch left, Nancy is eager for any guidance she can have. When she discovers the possibility that her grandmother, the most powerful witch of her time, might still live, she seizes her chance. Desperate for answers, Nancy journeys across the Cornish wilds to find her grandmother and uncover the secrets of The Mother, before it is too late.