It's 1995 and a girl in a blue dress walks down the stairs, through a party, with blood on her hands. The girl tells her friends it isn't her blood. She leads them upstairs to another girl, holding her baby in a bathtub, covered in blood. One of the girls berates the girl who just gave birth, telling her she's the worst Kappa pledge of all time. The new mom is apologetic, insisting she can walk if she can get some Gatorade.

The group of girls abandon the girl who gave birth and the girl with blood on her hands so that they don't miss TLC's "Waterfalls" which is playing downstairs at the party. The sorority sisters jam to the song, and eventually return upstairs where they find the girl who gave birth dead and the girl with blood on her hands holding the baby. The girl holding the baby asks them what the hell they're going to do.

Fast forward to 2015. Chanel, the president of Kappa Kappa Tau wakes up in the morning to the sight of her three minions, who she refers to as Chanel Number 2, Chanel Number 3, and Chanel Number 5. The Chanels wait on her hand and foot.

Chanel talks down to the sorority's maid, Ms. Bean, who she calls White Mammy. She berates Chanel Number 5 for being a suck-up after #5 gives her a gushing compliment.

Chanel is called to the Dean's office for a meeting. Dean Munsch tells Chanel that she hates sororities and hates Chanel, and also explains that she was promoted from Associate Dean to regular Dean after the death of Dean Reynolds over the summer. Dean Munsch details the ways in which the university's Greek life has run rampant and unchecked and pulls out the police report from the assault on Melanie Dorkess, Chanel's predecessor, that took place the previous spring.

We see a flashback to Melanie Dorkess berating Chanel for thinking she's Melanie's heir apparent, telling her she doesn't have what it takes and that she'd rather not have her around. She dismisses Chanel and asks her flunkies to spray tan her. It turns out the spray tan was filled with hydrochloric acid, and she becomes hideously burned. As the flunkies run out screaming and as Melanie writhes in pain on the ground, a devil-costumed, masked figure appears and stands over her, watching.

In the present, Dean Munsch tells Chanel that she thinks Chanel did it, though the police case was closed and the spray tan company settled with Melanie out of court. The Dean tells Chanel that this is personal for her and that she is taking Chanel and the sorority down, and is beginning by revoking KKT's charter.

Chanel and the Dean are interrupted by the president of the national chapter of Kappa Kappa Tau, Gigi Caldwell. Gigi tells the Dean that she can't revoke the charter. Gigi tells the Dean and Chanel that she is the sorority's lawyer, having graduated from a fourth-tier law school in the Caribbean. 

Chanel threatens Dean Munsch against messing with her, saying that her dad is the single largest donor to the university, and exits.

The Dean tells Gigi that regardless of not being able to revoke the charter, there is no way Kappa Kappa Tau will survive the year in its current state. Gigi agrees and mentions that she has a suggestion.

Grace is driven to college by her dad, who plays a sentimental playlist for her and reminisces about her childhood. He tells her that she's all that he has, and she is his best friend. Grace assures her dad that she will be fine because Wallace University is one of the safest in the nation. Grace's dad begs her not to join a sorority. She insists on it, mentioning that her mom died when she was 2 and that by joining the sorority it would be like she was following in her mother's footsteps.

Grace and her dad tearfully hug good-bye and Grace is left alone in her room. Grace's roommate Zayday walks in and introduces herself. They go to lunch where they exchange stories of their families. Grace mentions that her mother died, and Zayday explains that she was mostly raised by her grandmother who wanted her to be the first African-American female president.

Grace tells Zayday she plans on rushing Kappa Kappa Tau and tells her roommate that she should join. Zayday says she would rather die, but is eventually convinced when Grace mentions that becoming president of KKT would be a good place to start on her road to the American presidency.

Grace stands outside the KKT house and notices a devil-costumed figure (apparently the same one from the flashback who stood over chemically-burned Melanie) watching her. She follows the figure but doesn't catch up to it.

At the pledge event, Gigi announces that she and Dean Munsch were discussing modernizing the sorority. The Dean says that they are allowing anyone who wants to join entry into the sorority. The vast majority of the pledges leave. Chanel Number 5 storms off and goes to find Chanel. Chanel berates her for entering without knowing. #5 slaps herself to atone for her transgression and then tells Chanel she needs to follow her downstairs.

Chanel bemoans the state of their KKT pledge class. The pledges Chanel notes and mentally mocks are Neck Brace (Hester), Deaf Taylor Swift ("Tiffany something") and Predatory Lez ("Mack or Butch or something").

Zayday asks Gigi what's up with her outfit. Gigi explains that according to her therapist, she experienced a traumatic event that kept her psyche trapped in the 90's.

The doorbell rings and the Dean introduces Jennifer, a girl she found alone in the library. Jennifer introduces herself as a "candle blogger."

Chanel goes to talk to Chad and Boone, members of the Dollar Scholars fraternity. Chad tells Chanel that she needs to remain popular in order to remain his girlfriend. Boone angrily dismisses Chanel, telling her that Chad is great and doesn't have time for their discussion. Chanel tries to argue to keep their relationship intact, but Chad tells her he just can't date a "garbage person." Chad sends her away and he and Boone continue hitting golf balls at "hippies" on campus.

Chanel finds Ms. Bean and tells her that she has a plan to keep the sorority intact, and to make sure that "fatties and ethnics" don't get in. She takes Ms. B to a cafe and nastily orders a very specifically made, burning hot pumpkin spice latte from a young barista. 

Chanel tells Ms. B that her plan is to pretend to murder Ms. B to scare off the new pledges. She berates the barista for burning the milk in her latte and requests another barista.

The original barista returns to the counter and meet Grace, who jokes that she wants her pumpkin spice latte freezing cold. She orders a regular coffee and the barista jokes that he's in love with her. She introduces herself as Senorita Awesome and he apologizes to her for Chanel's obnoxiousness. She tells the barista that she is pledging KKT, to his consternation. When she leaves, he chases her out and tries to convince her not to join the sorority, telling her that he's also an investigative reporter for the school paper and knows that the house is actually dangerous.

Chanel interrupts them, calling the barista (Pete) a sex offender. She explains that he sent her many texts. He counters that he just had a crush on her and that she led him on for her own amusement. He begs Grace not to join KKT but she leaves, insisting she'll be fine.

The pledge class enters KKT. Chanels 2, 3 and 5 report to Chanel that #2 noticed Ms. B's bedroom door open, and shows Chanel that there was a creepy montage of scratched out Chanel faces. She storms downstairs, and summons the pledges, telling them she's going to deal with someone who disrespected her. She confronts Ms. B, who denies knowledge of the hate-shrine. She tells the pledges that she had planned a prank where she'd pretend to burn Ms. B's face off in fry oil that was actually cold, but that now maybe she'll just drown Ms. B in it instead.

Chanel dunks Ms. B in the fry oil but apparently someone turned the fryer on and Ms. B's face burns off. She collapses. The pledges and sorority sisters all scream. Chanel notes that Ms. B is dead.

Grace storms off, saying she is going to go inform the campus police. Chanel stops her, saying that she will report to them that Grace shoved Ms. Bean in the fryer. She successfully bribes the other pledges to back her story (except for Zayday) with promises of getting them cool boyfriends and taking them on her dad's jet to Cancun on Spring Break. Grace gives in to Chanel's demands and doesn't go to the police.

The pledges and sorority sisters carry Ms. B's body to the meat lockers. Chanel tells them they all share a secret, and threatens them all with death if they tell what happened to Ms. B. They go off to have cocktails.

Dean Munsch smokes pot in bed next to a naked Chad, and ponders how her life got to this point. She recalls burning her bra, and protesting for equal rights. She looks disparagingly down on the younger women at the college, and recalls how her husband left her for a 19 year old years ago. She insults Chad's sexual prowess, and bemoans how she is blackmailing students on academic probation for sex. He tells her he's in love with her but she scoffs at him and kicks him out.

Grace starts to tell Pete about what happened, but he guesses exactly what happened -- he was spying. She tells him she wants to help with his expose, showing Chanel for what she truly is. They leave to examine Ms. B's body.

Grace and Pete break into KKT to find the body but see Chanel and Chad show up. As Grace and Pete hide and watch them, Chanel tells Chad that the fryer wasn't supposed to be on and Chad voices that he is turned on by dead bodies, calling Chanel lame for not also being turned on by dead bodies. They open the freezer but Ms. Bean's body is nowhere to be found.

Chanel tries to lead a blood oath that she found on the internet, to ensure that her sorority sisters remain quiet about the murder. Chanel #2 storms off, saying that she is going home and calling her mom.

As Chanel #2 is packing, she gets a text message from an unknown number asking if she's brave enough to open the door. She opens it to the devil-costumed masked figure, who texts her rather than speaking. He stabs her to death, and with her dying breath, she sends a tweet saying she's being killed by the Red Devil.