Wings series (Aprilynne Pike)

When a plant blooms out of fifteen-year-old Laurel's back, it leads her to discover the fact that she is a faerie and that she has a crucial role to play in keeping the world safe from the encroaching enemy trolls.

As her senior year of high school starts, Laurel is just beginning to adjust to Tamani's absence when he suddenly reappears, telling her he must guard her against the returning threat of the trolls that pose a danger both to her and to Avalon.