Clay Jensen returns home from school to find a mysterious box with his name on it lying on his porch. Inside he discovers several cassette tapes recorded by Hannah Baker, his classmate and crush who committed suicide two weeks earlier. The tapes are mailed with instructions to pass them from one student to next, like a chain letter. On the tapes, Hannah explains to thirteen people how they played a role in her death. Curiosity and fear of exposure keep the people on the list listening to the tapes and through the audio narrative Hannah reveals her pain and her slide into depression that ultimately leads to her suicide.
If you've only read the book I recommend the audiobook as well. It's unsettling, especially if your listening through headphones. You're able to completely put yourself in Clay's shoes. There are two different narrators, Joel Johnstone as Clay and Debra Wiseman as Hannah.