Diana Bishop, historian and hidden witch, unexpectedly stumbles upon an enchanted manuscript in the Oxford Bodleian Library. This discovery forces her to return to the world of magic in order to uncover the secrets of magical beings. She is offered help by the mysterious geneticist and vampire Matthew Clairmont. Despite the longstanding mistrust between witches and vampires, they form an alliance and seek to protect the book and uncover the secrets hidden within while dodging threats from the creature world.
Matthew struggles to cope with his desires and leaves Diana alone with her enemies. And among them is the powerful sorcerer Peter Knox. Another dark twist for Diana takes place when a disturbing package emerges from under her shop door. Meanwhile, her relationship with Matthew is moving forward, but something is about to happen that will put them both in even more danger.
Tensions rise between the creatures as the witches learn that vampires are studying DNA. Matthew crosses the line when he returns to Oxford. Diana discovers his dark past before something unexpected tears them apart. Matthew and Baldwin race to save Diana from Satu's dangerous dark magic.