Diana Bishop, historian and witch, accesses Ashmole 782 and knows she must solve its mysteries. She is offered help by the enigmatic Matthew Clairmont, but he's a vampire and witches should never trust vampires.

Having escaped to hide in Elizabethan London, Matthew and Diana must find a powerful witch teacher to help Diana control her magic and search for the elusive Book of Life. Enemies are everywhere, the threat to witches is growing, and Diana and Matthew's romance faces a barrage of new threats, from within as much as without.