As the school mourns the death of Hannah Baker, her friend Clay receives a box of tapes with messages she recorded before she committed suicide.
Hannah makes friends with Jessica and Alex, two other new students. Justin doesn't show up at school, and Hannah's mother finds something troubling.
Jealousy and gossip take a toll on Hannah's relationships. As Alex struggles with feelings regret, the guys pressure Clay into getting drunk.
Hannah thinks someone is stalking her and sets a trap. Hannah's mother confronts the principal and Clay strikes back at someone who wronged Hannah.
Hannah and Clay connect at the school dance, but a crass rumor ruins the mood. Clay takes Courtney to visit Hannah's grave.
Hannah's date on Valentine's Day doesn't go as planned. Alex gets in a big fight at school and has to face the honor board.
Another student sabotages Hannah during a class project. Clay's nightmares about Hannah spill over into the daytime.
Inspired by a friend's poetry reading, Hannah pours her heart out. Tony confides in Clay about the night of Hannah's death.
Hannah witnesses a traumatic event at a summertime party. Clay tries to reason with Justin, and Marcus warns him that the worst is yet to come.
A distraught Hannah gets a ride home from the party. Jessica's behavior grows increasingly erratic, and Clay learns the truth behind a tragedy.
Clay and Hannah grow closer. While Clay spends a heartbreaking night listening to his tape with Tony, tensions boil over at Bryce's house.
Hannah winds up at a party after an argument with her parents. The students are served with subpoenas, and Justin wrestles with conflicting loyalties.
Hannah seeks help from Mr. Porter, the school counselor. Clay plays the new tape for Tony and weighs what to do next.
Five months after Hannah’s death, the case against Liberty goes to trial, with Tyler as the first witness. Clay finds a troubling photo in his locker.
Courtney makes a brave decision. Clay's memories of Hannah drive a wedge between him and Skye. Someone trashes the yearbook office.
Worried about threats against them, Alex and Clay urge Jessica to testify about Bryce. Clay enlists Tony's help to find a potential witness.
Clay hides a secret from his parents. Concerned about his reputation, Marcus lies in court. Jessica and Alex skip school together.
Tyler and Cyrus embrace their outsider status. Alex fights to recover his lost memories. Ryan and Mrs. Baker look to Hannah's poems for clues.
Clay tries to figure out where the Polaroids were taken. Justin shows up at school. Zach's revelation about Hannah takes everyone by surprise.
Alex blows up at Bryce. Someone blackmails Marcus. Clay testifies about a night he and Hannah spent together. Jessica experiences a flashback.
When Hannah's parents come under scrutiny, Jessica reaches out to Mrs. Baker. Justin struggles to stay clean. Clay reconnects with Skye.
Tyler goes out with Cyrus's sister. Chloe confronts Bryce about the tapes. Jess wonders if she's ready to date again. Mr. Porter wrestles with regret.
Tony opens up about his past. Sheri devises a plan to get into the clubhouse. Mr. Porter tries to help Justin. Zach and Bryce butt heads.
Chaos erupts at school in the aftermath of Bryce's testimony. Jessica tells Chloe about the clubhouse. Alex's memories come rushing back.
Threats against Clay and the others escalate. Tyler faces disciplinary action. Justin testifies about Bryce, putting his own future at risk.
One month later, Hannah's loved ones celebrate her life and find comfort in each other. Meanwhile, a brutal assault pushes one student over the edge.