Untamed (House of Night novel, book four) by P.C. Cast and Kristin Cast, 2008.
I read the first three books of this series earlier this summer, and then the fourth book came out. I loved the first book (Marked), while I felt the second and third books were just kind of. . . for lack of a better word. . . okay. However, I hoped that the fourth book would be better. I wasn't holding my breath when I started it. It didn't take long until I got into the book. This one "sucked" me in much quicker, which was great!
The series takes place at a House of Night, where teens and young adults who have been "marked" to become vampires (the marks a kind of henna colored tattoos of moons on their forheads). In this story, they do not have to die, really, to become vampires. Except, a new kind of vampire has formed. . . young marked vamps who did not survive "the change" and died. Except now the have bright red marks. . .
Zoe Redbird is the rising star - she's already a full vampire with tattoos over her body that form with each accomplishment. She's also only been marked for four months. She will be the new Priestess, and she knows that something evil is going on with the current Priestess. . . the question is, what? Zoe and her friends are back, after some major rifts, working together to try to solve the mysteries.
I really enjoyed this fourth book!