If I Die
by Rachel Vincent
Kaylee Cavanaugh is used to dealing with death. She's a bean sidhe, a singer of souls; it's her job to sing souls to the great beyond.
But when death tells Kaylee she's on the list to die in just a few days, that's a bit of a surprise.
To take her mind off of her definite impending death (turns out you can only avoid the Reaper once, and she did that when she was three), she decides that her math teacher has to die, too.
She hasn't suddenly become homicidal; it seems that her new math teacher is also an incubus who has been feeding off the lust of mothers, while working to impregnate their daughters with future incubi. He also has now set his sights on Emma, Kaylee's best friend.
With the help of Sabine (her frenemy), and Tod (something more than a friend), Kaylee is determined to take down the threat to all high school girls before he can take another life.
I spent almost the entire book going saying to myself, "She wouldn't. She wouldn't! She so would NOT do that!!!!" and then it was "She did WHAT?!?!" The books keep getting better. It's like a supernatural soap opera.