I Shall Wear Midnight is the fourth book in the Tiffany Aching subseries of Discworld.
In this story, there is an entity that is causing an increase of bigotry against witches, and naturally its prime target is Tiffany. The story was ok, but very short and the plot was pretty thin. The book was carried by the characters, who are all still a lot of fun. I liked that we got to spend a short amount of time in Ankh-Morpork, which isn’t a normal setting for the Tiffany books, and I especially liked that we finally got a tie back to the first Witches book, Equal Rites. The timeline is rather questionable, but I was just happy to see some reference to it.