A Shadow of Night (All Souls #2)

Picking up from A Discovery of Witches' cliffhanger ending, Shadow of Night takes reluctant witch Diana Bishop and vampire geneticist Matthew Clairmont on a trip through time to Elizabethan London, where they are plunged into a world of spies, magic, and a coterie of Matthew's old friends, the School of Night. As the search for Ashmole 782--the lost and enchanted manuscript whose mystery first pulled Diana and Matthew into one another's orbit--deepens and Diana seeks out a witch to tutor her in magic, the net of Matthew's past tightens around them. Together they find they must embark on a very different--and vastly more dangerous--journey.