This book starts off with Clay Jensen receiving a box on his doorstep. He soon finds out that inside that box, are tapes. Once he listens to them he hears Hannah Baker's voice. Hannah had committed suicide. She is gone. Clay wonders why he has these tapes. He later realizes these tapes are explaining why she decided to take her own life.
Hannah says in her tapes there were thirteen reasons why she had decided to kill herself. She explains on each of the tapes each of the situations leading up to her death. There are thirteen people that are in some way responsible for her death. Clay listens to her stories, worried about why he was sent these tapes. The tapes were only sent to the people who were responsible. Clay is confused. He had only really ever talked to Hannah once. How could he have done anything wrong? He listens to the tapes trying to find out more about her. Trying to understand why she did what she did.
Clay is searching for the answers he needs to understand all of that. He follows a map that was slipped into his locker a couple days before. He goes to the placed Hannah is telling him to to get the full effect of her life. Clay was devastated when Hannah had taken her whole life. He was hoping to get to know her more. He had a crush on her for a long time. If Hannah would have reached out to Clay he could have helped her. Instead, she pushed him away. She didn't want to get close to him. The tapes were sent to Clay so she could apologize for that. She sent them to him so he could understand what was really going on in her life.
