We've come full circle......and so I will now go back to my rating for book 1. Books 2 and 3 were wonderfully dark and fluid reads, which were book-ended by a series beginning and ending that were knitted together to form a continuous entity.The Original Sinners series is definitely different. It's going to push you out of your comfort zone. I remember reading the first book and feeling unsure how to feel about this journey that I'd started. Then I read books 2 and 3 and couldn't put them down. Who knew that I'd come to fall for a set of darkly twisted individuals? Whatever it is that's going on here, surely there's some voodoo magic involved because I kept wanting to know more.This is not really a review, but more a long ramble of my thoughts. I had quotes but decided to just free form this. Potential mild spoilers ahead if you haven't read up through book 3 of the series.First, a few smallish complaints.~ I could have done without Zach and Grace in this series. The story would have stood on its own without their presence. Grace as a pal for Nora? Uh, okay. That situation felt too forced, as if we were being coerced into believing these two women fell so easily into a friendship. Grace exploring her sexuality without Zach? Again I say...uh, okay. I could honestly care less.As much as I wanted other women in this series to take some of the worship away from Nora and her magical vagina (dude, even the book said so, which made me laugh hard), I didn't think bringing Grace in for the final book was the solution. Her part in the story felt completely tacked on, almost as if it needed to be there in order to justify why Zach was a character in book 1.~ Going to go ahead and tag my usual (yes, I seem to have one every review, so most of this isn't new) Nora rant, so if you'd prefer not to read my Nora frustrations, don't click this. It's no secret that I've never been a fan of Nora. I still feel like after 4 books that I know nothing about her other than everything she does and thinks about is tied to sex, even her job as an author and the friendships that she keeps. WHO is she as a person, outside of her sexual identity? Before you hit me with the obvious answer that this is erotica, let me riddle you this : We know all about who Soren is with his faith and calling, and who Wesley is and wants to be - and what moves them. Why didn't we get to know more about Nora, other than a laundry list of what makes her appealing to other people (most of it physical or aesthetic/presentation in nature, such as her infectious laugh). Even in the most sexually-free environment, there has to be more about a person which shapes them than their desire to be poly-amorous and have sex whenever and however it suits them. It's perfectly (and I truly mean this) fine that she's not going to be a married mom living in suburbia, but I felt like I never really got to know her outside of her surface personality-traits and looks. What about hobbies, goals, future plans, etc?I'm actually a bigger fan of young Eleanor. She liked to steal cars (hey at least she had one non-sexual hobby). The upcoming White Years series looks like it will be interesting, as we will be traveling back in time to life before the Original Sinners.~ The entire kidnap portion of the story served as a vehicle for flashbacks, a few of which I skimmed. I can't put my finger on it, but something just didn't hold my interest with this book the way I was glued to the pages with books 2 and 3. But let's get back to the goodness, shall we?~ As usual, the Wes part of the story was the big highlight for me. Soren only gets yummier and yummier. Soren plus Wes in the same room = entertaining.~ The Griffin and Michael interlude gets two very enthusiastic thumbs up!~ I liked the addition of Soren's niece. She was cute and I was a big fan of the role she played in the story.~ Nora did have a great scene near the end with Soren. I can't spoil it, but she was awesome with what she did. I thought it felt like one of those "long time coming" situations.The negative in this review probably makes it look like I didn't care for the book, which isn't true. I loved many of the character interactions and the sex scenes never disappointed. I do wish that the amount of flashbacks were scaled down because those dragged the story out to the point where I was thinking that at least a couple of the non-pivotal recollections could have been saved for another book. The Mistress wasn't a bad series ender, but it wasn't on par with the previous book in the series. I'll be rating this as a marginal success - definitely worth the read for sure, and I'm thankful for the fair amount of closure that we got. I would still recommend it for anyone looking to dabble in the realm of dark erotica. You won't find many authors out there who are able to seamlessly intermingle eroticism with a clever literary style the way Ms. Reisz can. This book provided from the publisher in exchange for an honest review.