I have no doubt that Caitlin Kittridge is a talented writer and expect great things from her future books. For me, though, there are a few issues that prevent me from giving Pure Blood a higher rating.
First, after the first book (Night Life,) I didn't realize that Luna was so emotionally involved with Dmitri. She'd only known him a few days and they hadn't spent that much time together. So I was surprised by how strong her feelings were for him at the beginning of the second book. The relationship just didn't seem to have been developed to that degree, yet. Still, okay, I can get past this, but, given that Luna was supposedly so attached to Dmitri and that she has suffered from not having a pack, it seems just a bit odd that she didn't allow Dmitri to bite her and make her a member of his.
Second, I never quite understood how Luna was "forcing" her cousin, Sunny, to stay with her. It seemed throughout the first book, until the very end at least, that their decision to be roommates had been mutual. But, now at the beginning of the second book her cousin has been "freed" from her obligation and has happily moved back in with their Grandmother. Huh?
Third, I found it distracting when, at the beginning of Pure Blood, Luna, an experienced homicide detective, doesn't know that petechial hemorrhage is an indication of strangulation or asphyxia. Anyone who's ever watched CSI, read a mystery, etc. knows this and I certainly would have expected a homicide detective to have this knowledge. Minor, I guess, but it still interrupted the fantasy.
Finally, and this is certainly nothing to do with the author and I did not factor it into my rating, the Kindle version is almost impossible to read in many places. Even when all the words do appear the font is difficult to look at for any length of time.