The Shadow of Night is the second in a series by Deborah Harkness.  Diana Bishop, a witch and her husband Mathew Clairmont, a vampire travel back in time to save their future.  They face court intrigue, the dangers of their illegal marriage and trust issues in their relationship.   I thought this was more intriguing than the first book, it was a great combination of historical fiction and fantasy.  I did have trouble with the pacing of the story, it  had moments where it needed to be pushed along to get back to the future.  Overall a book that is worth reading.