This one has a locked room mystery in it (is that what you call when all the suspects are in a room when a crime is done?) But it doesn't feel too genuine, as the crime is related to things that must have been planned in a group. And despite previous book best efforts, I don't know all the suspects well.
Oh, it also had a cool world with levitating rocks, which makes the previous shadow worlds pretty boring. And we don't get to see any more cool worlds.
Again, I was a distracted listener by the end, but it didn't feel like anything the book does could interest me too much, as, again, everything feels like it's a dream someone's telling me about. Really cool if I could imagine myself experiencing all that, but meh, if I have to listen to someone else's. Maybe if I was a younger reader...