She starts by sharing the story of her first kiss, with Justin Foley, who goes on to inadvertently spread a salacious rumor that begins the sequence of events leading to her suicide.
Hannah reminisces about her friendship with two other new students: Jessica, who moves frequently because her father is in the Air Force, and Alex, whom they met at a coffee shop.
In the present, Hannah's mother, Olivia Baker, seeks out the school principal about her suspicion of bullying and makes a disturbing discovery.
Later, Justin, Zach and Alex force Clay into the car with them by stealing his bike and scare him into silence about the tapes by driving over the speed limit.
Clay is now having both auditory and visual hallucinations of Hannah during the day, including seeing her dead body on the floor of the basketball court during a game and hearing her tape playing over the school's intercom system.
In the present, Marcus warns Clay the worst is yet to come and again attempts to scare him into silence about the tapes, this time by planting drugs in his backpack to get him suspended from school.
While Hannah is on her way to find a phone to call the authorities, the downed stop sign causes a serious accident at that intersection, resulting in the death of Clay's friend Jeff Atkins, which was incorrectly considered a drunk driving incident.
With Tony's support, Clay finally listens to his tape and is overcome with guilt to the point of contemplating his own suicide because he feels he did not do enough to prevent Hannah's death.
As the depositions begin, Marcus and Courtney deny their involvement in Hannah's death as much as possible while Zach and Jessica admit their mistakes.
Jessica finally tells her father about her rape while at school Clay reaches out to Skye Miller, his former friend, to avoid repeating the same mistakes he made with Hannah.
Jessica returns to school, as does Alex who survived his suicide attempt but has lost much of his memory from before it, including the contents of Hannah's tapes.
A group of protesters gathers at the court to demand justice for Hannah, but Jessica and Alex are both threatened to avoid revealing anything incriminating when they testify.
Clay and Alex try to encourage Jessica to reveal information about Bryce during her testimony, but she fails after seeing incriminating pictures of her stuck to the board in a classroom.
Marcus lies about what happened with Hannah the night they went out on Valentine's Day during his testimony (in order to protect his reputation) and briefly mentions Bryce, angering him.
Clay also finds a second Polaroid photograph in his locker, which shows Bryce having sex with an unconscious girl, alongside a note warning "He won't stop".
Mr. Porter finds a brick thrown through his car window, with a threatening note attached; he later confronts Justin's mother and is arrested after a violent incident with her boyfriend.
When Clay leaves the birthday party, he finds a Polaroid photograph left on his car, with a note reading "The Clubhouse".
After Marcus is blackmailed, he calls Bryce a rapist during a speech at a ceremony, in front of a large group of parents and students, in order to protect his own reputation.
He is then approached by Cyrus who invites him to join him and Tyler in vandalizing the school that evening, but when he does, he sees a group of students entering a storage shed next to the baseball field, which he correctly guesses is the location of The Clubhouse.
Tony is asked to testify, but chooses not to reveal that Hannah left him her tapes because he owed her a favor after she helped him evade arrest.
While testifying, Bryce lies and claims that he and Hannah had a casual sexual relationship, and that she falsely accused him of rape after he brought an end to it.
Clay becomes mentally tormented by hallucinations of Hannah, to the point where he contemplates both murdering Bryce and killing himself, but Justin manages to calm him down.
After the Baker trial concludes and the jury finds the school district not responsible for Hannah's death, both Bryce and Justin are arrested outside the courtroom for their involvement in Jessica's rape.
Mr. Porter is fired after a performance review, and Tyler is placed on a diversion program after one of his social media posts reveals it was him who vandalized the school.
Flashbacks: On the night of the Spring Fling, Clay and Tony help Tyler dispose of the weapons while Justin, Zach, and Cyrus assist with the police.
Present: Eight months after the dance, Clay is brought from school to the police station and questioned by Deputy Standall about Bryce's disappearance.
Sheriff Diaz presents underwear with Ani's blood and Bryce's semen to Clay, who denies knowledge of its origin.
Principal Bolan tells Jessica to publicly apologize for Homecoming or she will lose her position as student body president.
Flashbacks: Shortly following the Homecoming game, everyone's alibis are revealed: Tony was laundering money through the Mexican cartel for his family, Justin was dealing and using drugs at the docks, and Monty was sleeping with Winston.
Present: Ani shares details of Bryce's murder with Deputy Standall, claiming Monty's involvement due to his lack of a strong alibi.