When a free AOL CD reveals their futures to them via Facebook --- which hasn’t been invented yet --- estranged childhood friends Josh and Emma learn that making different decisions now will affect the outcome of their lives later.

Clay Jenkins returns home from school to find a mysterious box with his name on it. Inside he discovers 13 cassette tapes recorded by Hannah Baker, his classmate and crush, who committed suicide two weeks earlier. She explains that there are 13 reasons why she decided to end her life --- and Clay is one of them.