Grace visits Dean Munsch's office to get the information Munsch promised about the baby in the bathtub from 1995. Munsch pretends she doesn't remember saying that and blows Grace off, saying that Feather is the Red Devil and is behind bars. Grace claims that the Dean is going to refuse to confront what's going on until the Red Devils come for her personally.
At Dean Munsch's house, she prepares to take a shower. The Red Devil moves to attack the Dean, pulling back the shower curtain to find the Dean not there. Munsch sneaks up behind the killer and knocks them out. She runs out, calling 911 from the living room as the killer regains consciousness. She manages to successfully fight off the killer, only to be accosted by an additional two killers (two in Red Devil costumes and one in a Supreme Court Justice Antonin Scalia). Revealing that she was trained to fight by an ex-lover, she manages to disarm each of the three killers, and the limp out of her house.
Chanel gathers the other Chanels and asks them what they discovered in their quest to prove Zayday and Grace are the killers. Each of the Chanels present flimsy nonsensical evidence. Chanel insults them and then comes to the conclusion that she needs to pay someone to do the digging for her.
Chanel #3 encounters Denise Hemphill in the kitchen using the fryolator and asks what she's doing there. Denise recounts how she convinced the Dean to allow her to move in to Kappa house. #3 propositions Denise, offering her $3 million dollars to prove with 100% certainty that Zayday is the killer. Denise agrees.
Grace returns to the Dean's office, after the Dean was attacked by the killers. The Dean explains that when the murders started up she couldn't offer up information about the 1995 accidental death of the girl without implicating herself as an accessory after the fact in that crime. She admits that she hoped someone would eventually just shoot the killer and take care of the problem. She offers up the name of the girl who died in the bathtub -- Sophie Doyle. Grace bristles, asking if she's sure that's the correct name because her own mom's name was Mulligan. The Dean accuses Grace of being selfish and only wanting to find out about her own history.
Denise intercepts Jennifer the candle girl. Jennifer tells Denise a story that Zayday told her about being embarrassed by a bunch of rich girls in high school and how she said she'd get "real revenge" on entitled rich girls everywhere, saying that looking back on it that might indicate Zayday is a serial killer. Zayday emerges from the bathroom, having heard everything they said. She tells them both to stay away from her and challenges Denise to get a warrant if she wants to investigate her.
Later that night, Jennifer is attacked and murdered by the Red Devil killer mid-candle vlogging.
Denise reports back to the Chanels that she has no hard evidence pointing to Zayday as the killer. She suggests that a 10% advance of her $3 million would help her fund her investigation. Chanel says she has to leave for her date night with Chad (their "night of a thousand compliments," in which they sit across from one another and Chad compliments Chanel a thousand times). On her way out, the Chanels and Denise encounter Jennifer's dead body, decorated with candle wax and holding candles.
Grace and Pete discuss finding the identity of the dead girl, which Pete has been unable to do. Grace insists that the dead girl was her mom, and she always sensed it. Pete suggests that perhaps uncovering the identity of the Hag of Shady Lane (who they figured was one of the girls who took the baby that night) will help lead them to uncover the identity of the dead pregnant girl. They brainstorm and come up with the idea that the Hag, being crazy, may have spent time in the insane asylum that Dean Munsch spent time in as well.
They head over to the asylum, where they speak with the painter patient who shows them a painting of Gigi and another painting of Gigi with twin babies -- a boy and a girl.
That evening, the Dean gives a speech about Jennifer's death and announces that all campus activities are now shut down indefinitely, thanks to the killer's actions. The Chanels lead a candlelight tribute to Jennifer.
Chanel meets with two Scotland Yard detectives who she hired/convinced (by threatening the Dutchess of Cambridge) to investigate Zayday and Grace.
Grace confronts Gigi with her accusations and shows Gigi the painting of her with the two babies. Gigi plays dumb and psychoanalyzes Grace, saying that it would be convenient for Gigi to be the killer because it would take care of ending the killings and Grace reclaiming her father. She also reveals that she and Wes are engaged, to Grace's shock. Grace warns Gigi to stay away from her father and storms off.
The Scotland Yard detectives inform Chanel that they uncovered information indicating that Libby Putney (aka Chanel #5) is actively plotting to kill her. Chanel brushes them off and insults them, saying that she doesn't care and only wants to know about their findings on Zayday and Grace. The detectives report that they found nothing incriminating on either girl, but that they did find incriminating information on Grace's mother. Chanel looks at the file and announces that it proves that Grace is the killer.
Grace goes to confront Wes about his engagement to Gigi. Wes tells her that Gigi just went to the mall to pick up house decor and returned with an engagement ring, but that he just played along so that he could have sex with Gigi. Grace insists that Gigi is crazy and Wes laughs it off, saying that he'll tell Grace before he and Gigi get too serious. Grace puts two and two together, realizing that Gigi must have known her mother, and that by extension her father must have known Gigi when they were in college. She runs off, telling her father to stay away from her. Wes looks menacingly into the mirror.
Grace returns to Kappa house where she's confronted by Chanel, who ambushes her with the file about her mother. As it turns out, Grace's mother was the president of Kappa house who loved the song "Waterfalls" by TLC, and she hooked up with and conceived Grace that night (or shortly after) with Wes. She was an all around awful person and drug dealer, and Grace's father sued her for custody of Grace and Grace's mother died a year later. Chanel insults Grace's mother and claims that Grace was murdering everyone, thinking she was the dead Kappa girl's baby. Grace slaps Chanel and runs off.
Denise, dressed in Chanel #5's clothes, declares herself the "housemother," in charge of KKT. She tries to demand that the girls do charity work and community service, though they resist. Chanel returns and tries to put an end to Denise's takeover. Denise takes Chanel aside into the bathroom where she chastises Chanel about her insulting Grace's mother. She convinces Chanel to apologize by threatening that she'll place a booty call to Chad Radwell and steal Chad from Chanel. Chanel, horrified, reluctantly agrees.
Grace retrieves the one burned picture she had of her mother. She visits her dad and asks him to confirm Chanel's story. He admits that all of it is mostly true and tells Grace that he burned down their house so she'd never find out the truth. Wes insists that he was only trying to protect Grace. Grace warns him that she is her mother's daughter and that he should stay far away from her if he wants to protect himself. She leaves. Gigi enters the apartment and explains to Wes that Grace is failing out of school with a 1.4 GPA and that Grace has been on a downward spiral. Gigi suggests that Wes needs to take real action, like committing Grace, or else he is failing her as a father.
Grace meets up with Chanel. Chanel offers her apologies for ambushing Grace with the info about her mother. Chanel lists off the reasons her own mother was an even worse person who terrorized Chanel. Chanel insists that they all have mommy issues, and that she joined Kappa so it could be the mom she never had. Grace insists that Chanel is only continuing her mother's awful legacy and Chanel suggests she is a work in progress. Grace finally accepts Chanel's apology.
Elsewhere, Boone goes to a gym in disguise (wearing a beard that causes people to confuse him for Joaquin Phoenix). He gets a phone call from a third party. He tells the person that Gigi is their problem. He criticizes that she showed up to kill in an Antonin Scalia costume, and suggests that she is the weak link. He says that they need to take Gigi out and then finish what they set out to do.