Unearthly by Cynthia Hand

In the beginning, there’s a boy standing in the trees…
Clara Gardner has recently learned that she’s part angel. Having angel blood run through her veins not only makes her smarter, stronger, and faster than humans (a word, she realizes, that no longer applies to her), but it means she has a purpose, something she was put on this earth to do. Figuring out what that is, though, isn’t easy.

Her visions of a raging forest fire and an alluring stranger lead her to a new school in a new town… Read more.