Clay Jensen, a shy high school student, returns home from school one day to find that he has received a mysterious package in the mail. The package is revealed to contain thirteen cassette tapes recorded by Hannah Baker, a classmate who recently committed suicide. Before her death, Hannah explains that thirteen people, including Clay, are to blame for her depression. The tapes, which detail how each person drove her closer to suicide, are to be passed between the thirteen people, in the order they are mentioned. Hannah claims that she has given a second set of the tapes to an unnamed classmate, who will leak them to the whole school if the tapes do not reach the thirteenth person.