I guessed the murderer early -- okay, I thought there were three likely possibilities and that Black actually went for the least shocking -- but I don't much care. What I like about this series is the style, the worldbuilding, and the characters. Optional short story Lila Zacharov in 13 Pieces
just makes things even more delicious.
I didn't realize which exact genre of classic star-crossed romance Black was telling until the end, but it's perfect.