Grace, shocked, listens as Pete explains that he discovered who the Red Devil was weeks ago (Boone) and that he kept quiet because he realized their goals were the same -- to take down the Greek system. Pete admits that he killed Roger. Grace attacks him and tries to escape but Pete restrains her. He claims that he was forced to kill Roger because the Red Devils believed that he was a double agent and he needed to prove he wasn't. Pete also admits that he killed Boone, in an attempt to stop the murders, and that he shot Chanel with the crossbow in the mall and the police officer.
Pete also claims that Grace practically told him to commit the murders, after they visited Mandy in the trailer park. Pete admits that Chanel sexually humiliated him the previous year, tricking him into dressing up as a caveman only to embarrass him in front of the other Chanels. He tries to insist that he did all that he did for Grace and that the murders had to happen to clean up the mess that Chanel made of Kappa. Pete tries to convince Grace to run away with him. She tells Pete that she hates him and tries to leave but stays behind when Boone offers to tell her who the other killer was -- one of the Kappa sisters, who was Boone's twin sister and the other baby in the bathtub.
Pete explains that he collected DNA samples from all of the Kappas. As he is about to reveal who the other killer is, the remaining Red Devil appears and stabs him. Pete dies. Grace fights off the killer, but the killer gains the upper hand and knocks Grace out.
Chanel is attacked by rioting students, who came back to campus because of the "missive to end all missives" that she wrote, a scathing letter directed to the Chanels and Zayday attacking them for missing the appointment to drown Munsch at the pool. The email got forwarded to everyone and went viral, resulting in news coverage about Chanel being "the most hated woman in America" and her being publicly shamed. Chanel, despite outwardly projecting that she doesn't care about her reign of terror being over, resolves to kill herself.
Chanel purchases a snake, intending to commit suicide by asp. Zayday explains that the snake she ordered online is actually a harmless garter snake with a sweater on it and convinces Chanel not to kill herself and that she should be a better person instead. They agree to work together, joining forces to find the killer.
A Red Devil attacks Zayday and Chanel. He is very inept at attacking them and when Zayday rips off his mask, he shouts in a panic that "she" made him do it. Chanel and Zayday drag him to the lobby and call in the Chanels. Hester tries to tell Chanel that a woman wearing a shawl with scars all over her face showed up saying something about "Dork" and carrying a shovel.
The man reveals that he is just a pizza delivery man. He delivered a pizza to the house and someone wearing the Red Devil costume attacked him. When he woke up, the killer had wrapped him in dynamite and told him that if he didn't kill everyone in the house, she'd detonate the bomb. The Chanels scream frantically and take cover as the pizza guy explodes.
Men in Hazmat suits clean the crime scene. Chanel explains that she is a changed person since Zayday convinced her not to kill herself. She decides that she must go on an apology tour, starting with Melanie Dorkus. She explains that after what Hester said, it's clear that Melanie is stalking the campus. She intends to apologize to Melanie, though she still denies having put the acid in the spray-tan machine, and wants to have the Chanels capture it on tape and release it to the public to repair her image.
Grace is at Wes' apartment, wondering along with her father why the killer let her live. She explains that she didn't have sex with Pete. Wes is grateful that didn't happen, but tries to convince Grace that despite Pete's actions, he seemed to be a good person and that Grace should not doubt her instincts because of the reveal about Pete. Grace insists that they need to figure out as much as possible about the remaining sisters in order to determine who the last killer is, the baby girl in the bathtub. She tells Wes he will need to make the most important playlist of his life and take one for the team.
Dean Munsch enters her house and finds it filled with candles. Thinking she is about to be attacked, she sneaks over to her room and finds Wes in underpants on the bed. After initially being suspicious of his motives, she gives in and they begin to have sex. Meanwhile, Grace and Zayday sneak into the house and search for clues as Wes distracts Dean Munsch.
The Chanels go to Melanie Dorkus' house to meet up with her, convincing her butler that she is expecting them. Hester is planning to meet them there, which #3 comments is odd.
Back at Kappa house, Hester steals jewelry and lurks in Chanel's closet.
At Dean Munsch's house, Zayday and Grace go through the Chanels' files. They realize that one of the files is entirely made up and become convinced that the girl whose file it is is the baby in the bathtub and the last remaining killer.
At Melanie Dorkus' house, as they are waiting to see Melanie, Chanel #5 suddenly gets a message on her phone. She tells the Chanels that she needs to leave because someone swiped right on her on Tinder for the first time ever. Chanel mocks her, calling it a miracle, and agreeing that she should go. #5 leaves.
In bed after sex, Wes is stunned at how good the sex was. Dean Munsch expects him to admit that he only had sex with her for information on the murders. Instead, Wes tells her that they had the best sex of his life and that they should be together, for real. Munsch is confused but then gives Wes an ultimatum -- if they are to be together, Grace needs to go. Munsch tells Wes that if he wants to continue what they have, they need to find a way to make Grace go away for a little while.
Chanel and #3 go in to visit Melanie and are shocked by how messed up her face is. Melanie explains that she was previously living in Alaska but that her parents believed it wasn't healthy to be living in an arctic compound on her own and moved her back to town six weeks ago. As Chanel #3 starts recording Chanel's apology, Chanel suddenly attacks Melanie, insisting that she is the killer. Zayday and Grace barge in and stop Chanel, explaining that Melanie isn't the killer -- Hester is.
They go back to the house and find Chanel #5 there, her Tinder date having been a fake profile for Chad Kroeger of Nickelback. They find Hester upstairs, with a shoe in her eye socket, apparently dead. They are all confused. Suddenly, Hester awakens and points at #5, accusing her of being the killer.