What can I say about this book that you already don't know? If you've read previous three books that mean that you liked it or otherwise you would have stopped after the first one. 
 It is no secret that I love Diana Rowland. She writes great books that make me postpone my everyday life just to have a moment alone with them. 
 "Sins of the demon" was no exception. Ms.Rowland as a former cop provides us with the inside look at the police work. It differs from what we see on the TV shows but this exact contrast make "crime" part of the book very believable and engaging. 
 Moreover, she created one of my favorite lead protagonist. Because Kara in awesome! Her awesomeness is like universe - ever expanding! But I like all of the characters. In this book we see a lot of Eilahn, who provide me with much needed laughter. I do hope we will see her in the future books too. 
 A lot of reviewers are upset because of lord Rhyzkahl absence (he appears only in one scene). Unlike them, this fact makes me very happy. I HATE RHYZKAHL!!! From the first book he aroused only dislike in me. He is an ASSHOLE! I think that their relationship is very abusive. He manipulates and tries to control Kara. When she asks question he didn't want her to, he distracts her with sex. And when he is not happy he turns his rage on her. Of course he never physically abused her, but in every book he does some bad things to her. They are not equal, they don't trust each other, he doesn't respect her and she is afraid of him. So what kind of relationships can there be?! So yes, I was very glad that this book paid more attention to Ryan. 
 And while this book was not so much on "solving a murder" part as more to figuring out what is happing in the big picture, the suspense was still good. We learn more about Ryan, about old murder of six summoners, about demonic lords' plans for human realm and about Kara's parents' deaths. And even it was just little pieces of the puzzle and I still can't assemble them in the final picture, it looks very promising. I can tell that the next books won't be boring. 
 "Sins of the demon" ended with a BANG! Major cliffhanger. I don't know how I will wait over a year for the next book to come out. 
 I have this ridiculous wish to get on the plain, fly to USA, find Diana Rowland and on my knees beg her to tell me what will to happen next. 
 Maybe I should do it. Maybe a person living on her front lawn will motivate her to write faster=)) What do you think?