The official trailer for 13 Reasons Why opens at a high school, and a young couple greet each other. At the school dance, the boy, Clay (Dylan Minnette), tells his girlfriend Hannah (Katherine Langford), “He is not going anywhere, not now and not ever.”

In a surprise reveal, she asks him why he did not say these things when she was alive. Clay finds a box waiting for him on his front porch. Inside the box are cassette tapes, and when he plays them, Clay is shocked to hear Hannah’s voice. She says whoever is listening to the tapes will hear the story of her life and why it ended. Hannah also reveals that the listener of the tapes is one of those reasons why. This prompts Clay and the rest of the students to try to unravel the mysterious circumstances of Hannah’s death.