Eat, Prey, Blood by Betsy Russell
What would you do if you found out your parents were keeping a secret from you? A huge, life-changing secret? Sixteen-year-old Katie wasn’t looking forward to spending an entire summer helping her dad at his archeological dig in Italy. At least, not until her two best friends let slip that Katie’s dad isn’t exactly the person she thought he was. In fact, he’s not even human, leading Katie to question who—or what—she is. Add in a missing book and a mysterious man in a black coat, and Katie realizes her boring summer might end up as something else entirely.