Shattered Mirror

In this third installment in the series that began with In the Forests of the Night, Atwater-Rhodes focuses on teen witch (and vampire killer) Sarah Vida, who "never asked for anything more complex than the simple goodand evil definitions she had been raised on" but gets more than she bargained for when she befriends vampiresiblings Nissa and Christopher. This is trouble: it's harder to kill when you know your prey, and her mother the most infamous witch of all will disown her if she finds out a