The Riley jenson series is like brain candy. There's not too much extra thought processing that I need to do. There's really no deeper level than what is actually going on in the story as you're reading it (not that I can see anyway). I don't like all of my books this way but sometimes it's a nice departure. The fourth book in the series is no different. 
 After the events from the last book Tempting Evil I wasn't sure where our characters would be headed. The first three novels focused on Riley and Co. finding out who was behind the cloning scheme. That done and out of the way, we are able to embark on new adventures. I can't tell you if this book was a "bridge" book between that ending story arc and another yet to come becuase I don't know what is to come in the remainding books in the series. 
 Of the series so far I would say this story is the most steeped in "mythology" I guess is the best worked to describe it. It's less about working being studied for the future (like the clones) and more about containing an old evil. Yet with that said, I think this storyline is also one of the weakest / confusing. This may stem from the fact that Keri Arthur was on new ground in regards to this series. As stated before the other novels were all following one story arc and this is the first one that branched off. That may be why the storyline seemed a bit awkward. I mean we start out the story with two potential cases and somehow they end up merging into one case. I can't even really remember how this happened. All of a sudden I found myself along with the characters all hunting the same people for the deaths of multiple women. 
 This story actually cuts the last thread of storylines left over from the beginning of the series. So the 5th novel should start out completely fresh with nothing being picked up (as far as the "cases" go, the relationships span the length of the series). 
 Maybe the storyline was meant to be second in terms of importance in this book, because the relationships seemed to be front and center. Things between Riley and Quinn finally come to a head in this novel. It's difficult to really have an opinion for me because I honestly agree with Riley's sidfe of the story, but I just really like Quinn as a character. I think he's one of the most strongly written characters of the series so far, and I enjoy every time he is on the page. On one hand I also partially agree with his side (not liking that fact that Riley sleeps with various men because of the "moon"). 
 This book was both lighter on the sex and heavier on the sex if that makes any sense. In the previous books we have Riley sleeping with multiple people multiple time throughout that whole book. In this one we see her with Kellan (who we've come to know as now one of her regular partners) and we see her with Jin. That's all. I liked that the book seemed lighter on the sex and more focused on the people. I hope this continues in later novels because honestly we've seen Riley have sex, we know she enjoys it, it's nice to know there might be more to her relationships besides sex. 
 With that, however, I also said that this one was heavier on sex. Meaning that sex with Jin is the "pleasure from pain" kind of sex and honestly I didn't care for that detail at all. It was difficult to read those parts of the books (it plays a pretty significant part within the story). I was a little angry that even though it was something Riley didn't like, she did it anyway. She let herself be beaten because some guy found it hot because it would help the Directorate solve the case. Maybe we are now seeing how far Riley will go to get the job done? She does walk away from it, and at this point I was happy that she did, but then she walks right back in because Jack told her to. She didn't (at least on the page) try to tell Jack what this guy was about and that she wasn't comfortable. Either because she knew he wouldn't care (which is disturbing) or because despite her ranting of "not wanting to become like the other Guardians" she really would give up her morals to get the job done. In this regard I don't see eye to eye and I didn't care for it. 
 The main thing that saved this book for me was the new direction Riley and Quinn's relationship takes in this book. I'm anxious to see how it all plays out down the line. I will continue to read the series to end hopefully this was just a little bump in the road for the series and we will get back on track next time. Until then!