This review was first posted on http://www.rubysreads.com.

Oh, Rune! How do I love thee? Enough to overlook your appalling dress sense, certainly.
Ahem. Sorry, this is meant to be a book review, not a hero review. Although... No, never mind. I admit that, when I heard who Rune's heroine was going to be, I was a trifle disappointed. I can't explain why exactly, but it's probably due to the fact that I tend to dislike world-weary been-there-done-that heroines. I should have known better. I should have expected more from the very awesome Thea Harrison. Because not only did she make me like Carling, she made me really like her--and root for her and Rune.
I loved this book, but I have a confession to make. I'm still a little bit confused about the plot. It involves time travel, which is basically a big flashing red light that there's going to be something in it to confuse me. Time travel plots always make me go, "Wait...What...?" and "But, didn't...?" I think my brain shuts down in self-defense. I leave the physics to my brother and his Ph.D, and focus on the parts that interest me more. I.e., the hot heroes, the romance and the world-building.
It's well-known (I hope) by this point that I'm a huge alpha hero fan. Also well-known? Thea Harrison absolutely knows how to create them. Rune is an alpha hero who Does It Right. He perfectly personifies that sexy-scary hero Thea Harrison describe in her Book Boyfriend post this week. He pushes Carling when he knows she needs it, and need it she does. It's a sort of role reversal. In Serpent's Kiss, Carling is the cold, closed-off half of the couple and Rune is the one that encourages her to feel by not kowtowing to her immense power. He's also the one that encourages her to relax and have fun--he plays the role usually reserved for the quirky, off-beat heroine.
Harrison also continues with her fantastic world-building. I'm not going to touch on the time-travel plot (for the reasons mentioned above), but I will say that the trips back in time really worked for me in terms of expanding Rune and Carling's relationship. It happens at lightning speed, which is kind of the formula for Harrison's books. It really needs the extra connecting that happens during the time jumps. I also really dug the vampire lore, and how the concept of the serpent's kiss played into the world's concept of vampirism. The more I learn about Harrison's world, the more eager I am to visit the other demesnes.
The last thing I want to touch on is Thea Harrison's talent for introducing new characters. We met Duncan and Khalil in Storm's Heart, but we get to know them better in Serpent's Kiss. I absolutely adore it when authors build up anticipation for characters stories. It's one of the things I love best about Nalini Singh, and I'm giddy with excitement to find an author who can do it with as much success. There's an excerpt for Oracle's Moon at the end of Serpent's Kiss, and it did miraculous things to whet my appetite. Thea Harrison can't write fast enough for me.
5 Points: I would move in with this book.