This picks up right where the cliffhanger that was book 4 (Sins of the Demon) left off. Kara has been summoned to the demon realm by Mzatal. She's unbalanced and needs to figure things out quickly.
I had a harder time with this one than I thought I would. What I enjoyed about the previous 4 books was the paranormal police procedural. And Jill, Tessa, Eilahn, Zack, and Ryan. That is not this book, at all. Kara's friends make an appearance at the end.
The first half of the world is definitely more world building, demon realm 101. It was both dry and interesting, but I found my attention drifting and would put the book down to read later. It picked up about the halfway through. Answers abound in this one. Kara does some stupid things (and I was disappointed, but oh well). Overall, this lacked the enjoyment for me. Enough so that I may or not may read the next. I haven't decided.