I'm just recently getting around to reading these. I finished A Discovery of Witches and immediately launched into the sequel, Shadow of Night. While enjoyable, for much of the book it seems as though the plot isn't really moving forward. Everything seems to progress towards the end, and I tend to find that frustrating. However, I really like the main characters, and the supporting cast of real and imagined historical figures is delightful. The furthering of the main characters' relationship is touching, and the little touches Harkness places throughout make this a worthwhile read.
A follow-up to the best-selling A Discovery of Witches finds Oxford scholar and reluctant witch Dina and vampire geneticist Matthew Clairmont in Elizabethan London, where Dina seeks a magical tutor and Matthew confronts elements from his past at the same time the mystery of Ashmole 782 deepens. Reprint.