The cover of the book made me think this would be a scary ghost story, but although it is a ghost story, it's also a love story, a self identity story, a story about family, religion, and the after life. Helen is a ghost who has been haunting earth for 130 years. She passes from host to host, and they can't see her or talk ot her, but for the most part they can feel her presence even though they don't realize it. One day she notices that a boy in her latest host's English class is looking right at her. This unnerves her until she realizes that the body of the boy is being inhabited by a fellow ghost. Slowly details about her life and this other ghost's life are revealed not only to the reader, but also to the characters themselves, and topics such as religion, teen angst, romance, and the after life are also explored. The writing is really good and the characterizations are as well. Since there are scenes of a sexual nature in the book, I would say 14 or older for this one, but I would recommend it.