I've been enjoying this series a lot, but some reviews on Goodreads made it sound like this was one of the weaker entries in the series. I actually quite enjoyed it, possibly because I had tempered my expectations. This time Eve is the narrator, a character that has so far mostly only appeared as a topic of conversation since she is dead. However, Armstrong opened the door to the afterworld in Industrial Magic, so Eve's appearance is not a complete surprise. Since Eve is a ghost, this means that there is a limit on how many of the other characters show up in the novel, but Eve's motivations are driven by her daughter's safety so I actually enjoyed this slightly related side story. Besides, Jaime Vegas is a necromancer so Eve soon convinces her to help, and it was fun to see more of her.
The Nix, an evil spirit, that has caused chaos and havoc in the past (and is more powerful than others of her kind for reasons explained early on), has escaped from her otherworldly prison, and the Fates engage Eve who owes them a favor to hunt her down. Part of this is because Eve enjoys breaking rules so much that she has gained quite a bit of knowledge about the different paths and places in the afterworld, and is very good at getting around quickly. Kristof Nast, Savannah's deceased sorcerer father, is also a very prominent character in the novel since he is trying to use the afterlife as a second chance to rekindle his romance with Eve. The two of them enjoy quite a few different adventures as they try to track the Nix, and do some detective work, linking her to past killers and victims. The Nix basically works by finding people that want to kill someone already and helping them find the conviction to actually go through with it, except as a spirit that feeds on chaos, she also enjoys then leaving them behind to watch them deal with their inevitable capture - one former partner includes Lizzie Borden.
This one was a lot of fun, and after five books, I'm happy to say that I'm still thoroughly enjoying the series and all of its characters. I think using shifting narrators helps keep the story lively, and by limiting other characters to shot outs or a short phone call, it gives the audience what they want without getting to the point where she is simply filling each book with references to other characters. I'm trying to pace myself on this series instead of burning through it since I know the novels are always reliable entertainment but it is tempting to finish the series quickly. I have to say I am curious about Armstrong's newest series, though, so I may pick up the pace.