Historian Diana Bishop, descended from a line of powerful witches, and long-lived vampire Matthew Clairmont have broken the laws dividing creatures. When Diana discovered a significant alchemical manuscript in the Bodleian Library, she sparked a struggle in which she became bound to Matthew. Now the fragile coexistence of witches, daemons, vampires and humans is dangerously threatened. Seeking safety, Diana and Matthew travel back in time to London, 1590. But they soon realise that the past may not provide a haven.