I write this review with a heavy heart. I LOVE Cat and Bones.They're the cutest couple out there. But their story should have ended 2 books back. 
 The first 2 books were vital for the story and super amazing. The 3rd book was a filler but at least provided us with a backstory on Mencheres. 4th book was far fetched but gave us a conclusion to Cat's dilemma. That's it. Why didn't you just quit while you were ahead Jeaniene? We're able to stomach a 5th book but no more! 
 Having run out of adversaries for Cat (Vampires first then ghouls), Frost created a threat in the form of a ghost.... 
 Sirius is not impressed either. 
 The extremely random plot introduces Elizabeth, Fabian's old ghost friend, who tells Cat & Bones about the ghost of the evil witch hunter that killed her, Heinrich Kramer. Apparently Kramer torments people all year long until he becomes solid on Halloween, which is when he selects 3 women to shun as witches and burn at the stake. Oh, and this has been happening for years. 
 Are you telling me, that in world infested with Vampires and Ghouls who believe ghosts are harmless, NO ONE noticed that there is a very powerful ghost that has been floating around for centuries? Also, why would Elizabeth wait this long to seek help? Why didn't she go to the Voodoo Queen a hundred of years ago? 
 It's not that bad of a plot compared to other shit out there but it's trying too hard. There really is not much more to add to Cat & Bone's story and this is a desperate attempt to keep them alive. The side plot was super lame as well, not gonna even get into that. Sadly, the subplot sets up the story line for book number 7. Surprise, Surprise, this time the threat is human! Vampires, check. Ghouls, check. Ghosts, check. Ah, yes! I haven't thrown human threats at Cat & Bones yet, let's try doing that! Ugh. I would have quit at book 6 but book 7 is the last book, so might as well. #Firstworldproblems 
 Another sign of desperation is the increased sex scenes. Cat & Bones relationship is awesome and super cute. However, we don't need added steamy scenes between them to convince us that they are still going strong. Again, they just served as page fillers and a respite from the boring plot. 
 As heartbreaking as it is, this series is long over due an ending. On a positive note, the spin off books are great, so that's something to look forward to.