"Daughter of Smoke and Bone" is about this girl named Karou who lives in Prague. Karou is very mysterious and doesn't know where she came from, but knows that her only family, are half humans called Chimera. She soon finds out that there are other worlds beside her own, and that if she wants to keep her friends and family alive, she might have to go and explore unknown places.
I think that this book is for ages 13+. I am 12-13 but I read adult fiction daily... Just the concept of it, the inside story, would need an older mind to keep straight what's happening. Some of my friends read it, and they got lost, and didn't end up with the same conclusions. It's all just a matter of how experienced a reader you are.