A Discovery of Witches (All Souls Trilogy #1) by Deborah Harkness

Deborah Harkness’s sparkling debut, A Discovery of Witches, has brought her into the spotlight and galvanized fans around the world. In this tale of passion and obsession, Diana Bishop, a young scholar and a descendant of witches, discovers a long-lost and enchanted alchemical manuscript, Ashmole 782, deep in Oxford's Bodleian Library. Its reappearance summons a fantastical underworld, which she navigates with her leading man, vampire geneticist Matthew Clairmont.

Harkness has created a universe to rival those of Anne Rice, Diana Gabaldon, and Elizabeth Kostova, and she adds a scholar's depth to this riveting tale of magic and suspense. 

Series: All Souls Trilogy (Book 1)
Paperback: 592 pages
Publisher: Penguin Books; Reprint edition (December 27, 2011)