This book was very sad. Clay finds a box of tapes on his doorstep. When he starts listening to them, he finds they are from Hannah, a girl in his class who committed suicide. They address 13 different people and are to be listened to and then passed to the next person. As he gets more engrossed in the tapes he finds himself more and more upset. Seeing how others unknowingly affected Hannah's decision. Including himself. 
 I really felt for Clay on what he was hearing, and hannah for not seeing that there were other options.