Shattered Mirror (Den of Shadows #3)

To the casual observer, Christopher Ravena and Sarah Vida look like normal high school students. But he's a vampire who has sworn off human blood, and she's a witch, a daughter of the most powerful vampire-hunting dynasty in history. Slowly, without meaning to, Sarah finds herself won over by his sensitivity, his gentleness, his kindness.
But his past and her future collide when they both get tangled up with Nikolas, one of the most reviled vampires ever.