Seventh Earth — Richard Bradford

Seventeen-year-old Aura Maples is a bright, quirky kid with little patience for the gossipy dating scene in her northern California hometown. Between school and helping her single mom, she reads, daydreams among the redwoods, and keeps mostly to herself. But after mysteriously passing out in English class and falling in love with the engaging, athletic “new kid” in school, she realizes that getting through senior year at Willits High under the radar may be a little tougher than she thought. And as if all this weren't enough, her body is going through some very strange changes that have nothing to do with the hormonal madness of late adolescence.
At her wits' end looking for answers, Aura finds herself face to face with a stranger who seems to know exactly what she's going through and why. But there's more in the bargain: along with the desperately sought answers comes a mind-blowing story that will change her -- and perhaps everyone's -- life forever.