A scholar specializing in the history of science and medicine, Harkness's career in fiction began in September 2008 when she began to wonder "if there really are vampires, what do they do for a living?" Her first novel, A Discovery of Witches (2011), was the unexpected answer. The book debuted at No. 2 on the New York Times bestseller list and went on to be a bestseller in the UK, France and Germany.
In The Book of Life, the third novel in the All Souls Trilogy (after Shadow of Night), witch historian Diana Bishop and her vampiric husband, Matthew Clairmont, freshly returned to the present from their sojourn in Elizabethan England, have ample challenges to contend with. They still seek the missing pages of Ashmole 782, the mystical manuscript known as the Book of Life and the key to the origin of all supernatural beings. But now they must negotiate the internal politics of Matthew's extended vampire family. With more than a million copies sold in North America and appearing in thirty-eight foreign editions, A Discovery of Witches and Shadow of Night have landed on all of the major bestseller lists. This eagerly awaited finale brings a superbly written series to a satisfying close.