A group of female students are stalked by a stranger during their Christmas break. That is until the young sorority pledges discover that the killer is part of an underground college conspiracy.
At Hawthorne College, a group of sorority sisters are being attacked by cloaked and masked figures. This turns out to be part of a ritual involving the fraternity that upholds the sexist traditions of the school’s founder, Calvin Hawthorne.
Riley Stone and her sorority sisters receive messages from someone claiming to be Hawthorne. After three of her friends are killed, Riley and fellow sister Kris get help from another sorority that is being attacked. They find that the frat pledges are being used to be possessed by Hawthorne’s spirit to give them super strength and to keep women from overpowering them. This fails as the sorority sisters fight back, and Riley kills the former president who raped her. Kris burns their leader, Professor Gelson, while the ladies lock the brothers inside to burn to death.
While walking home, Hawthorne College student Lindsey is impaled with an icicle by a trio of masked figures. The rest of Hawthorne College is preparing for the Christmas holiday break. Riley Stone, a student at the College’s MKE sorority, is still struggling to move on from being raped by AKO fraternity president Brian Huntley (which no one besides her close friends believed her about despite Brian being forced to leave). Her sorority sisters Kris, Marty, Jesse, and Helena are taking part in the AKO talent show with a dance choreographed by Riley. Riley gives Helena her lucky comb. Meanwhile, Kris has drawn the ire of the AKO fraternity and Riley and Marty’s lecturer Professor Gelson following a petition from her requesting that university founder and notorious misogynist Calvin Hawthorne’s bust be moved away from the main building and another requesting Gelson be fired due to his refusal to teach books written by women. While at her job at a coffee shop, Riley learns that Brian will be back in town to oversee the talent show. She also meets Landon, a friendly boy from the AKO fraternity who takes a liking to her.
The group arrives at the AKO fraternity where Riley catches a glimpse of a strange ritual involving new pledges for AKO and a black goo leaking out of the Calvin Hawthorne bust. She also stumbles across Helena about to be sexually assaulted by one of the frat boys. Riley intervenes and sends a tipsy Helena home. Riley takes Helena’s place in the talent show and upon seeing Brian in the crowd, performs a song with her sorority sisters blasting the rape culture at the fraternity and stating that Brian did rape Riley. The girls leave in high spirits and Riley bonds with Landon. Meanwhile, back at the MKE house, Helena is abducted by Lindsey’s attacker. The next day the girls start to receive threatening DMs from a Calvin Hawthorne account similar to what Lindsey had received before she was murdered. Meanwhile, sorority sister Fran is also killed by the masked man. Concerned that Helena has seemingly not gone home to her parents as planned, Riley alerts campus security who are apathetic and assume Helena has run off with a boyfriend. After a strange encounter with Gelson outside the AKO fraternity, where she finds a list of the MKE girls among some papers he dropped, Riley returns home.
Marty and her boyfriend Nate have an argument and she kicks him out of the house that night while Riley and Kris argue over Kris’ uploading the talent show video online and Riley now fears retaliation from members of the fraternity. Jesse goes to the attic to get some Christmas lights and is murdered, her body left in the attic. Riley, Kris, and Marty receive more threatening messages before being attacked by a bow-wielding assailant who injures Marty. The girls lock themselves in a room and Riley ventures out to retrieve her phone. Meanwhile, Kris goes to the attic to warn Jesse and discovers her body. Nate arrives back at the house looking to apologize and is promptly murdered. Riley then uses Nate’s car keys to kill the masked man. She reunites with Kris and Marty and they are attacked by two other masked men. Marty is gravely wounded but manages to buy Riley and Kris enough time to hide in the kitchen before dying. The pair overpower and kill the attacker. They remove his mask after being alarmed that they are covered in black goo instead of blood. Riley identifies him as an AKO pledge she saw at the ritual and is alarmed by a strange look in the pledge’s eyes.
The pair escape the house in Nate’s car and Riley theorizes that Hawthorne, who was known for dabbling in black magic, is responsible for the killings via his bust and the black goo it emitted. Kris shoots down the idea and suggests they go to the police but Riley demands they go to the AKO fraternity to fight. They argue and Riley heads off to confront the frat herself. She encounters Landon and enlists him to help her enter the fraternity. Meanwhile, Kris stumbles across Lindsey’s sorority, which had angered AKO for not wanting to take part in the talent show. She discovers Lindsey’s sorority sisters are also being attacked by other AKO pledges and manages to rescue them. At the AKO house, Riley and Landon break in, but Landon is cornered by the frat brothers who convince him to be a pledge. Riley witnesses the Hawthrone bust leak the black goo before discovering Helena, who is tied up but still alive. Attempting to rescue Helena, Riley unties the bonds securing Helena’s hands behind her back but is suddenly knocked unconscious by an AKO member.
Riley awakens to find herself sitting tied up on a chair. She is confronted by Gelson, Brian, and the AKO frat boys who have inducted Landon as a pledge. Gelson explained that after Kris forced the bust’s relocation to the fraternity they discovered Hawthorne’s plan, involving a spell and the black goo, to keep unruly women in check. The goo allows the spirit of Hawthorne to possess the fraternity’s pledges and send them out to murder any women that stepped out of line. It is also revealed that Helena has been secretly working with the fraternity and stole several items from her sisters that allowed the possessed pledges to easily locate their targets. One of the pledges murders Helena despite her willingness to be a “good woman” to the frat as a show of power to Riley. Brian forces Riley to bow to him, but she plans to attack him; at the same moment Kris and Lindsey’s surviving sorority sisters enter and fight the fraternity. Riley overpowers and kills Brian. She then smashes the Hawthorne bust. Kris sets Gelson on fire and the women and Landon escape, locking the frat brothers inside and leaving them to burn to death. As the traumatized group watch the frat house burn, Riley watches with newfound bravery.
In a post-credit scene, the cat that was the MKE sisters’ pet is seen licking the black liquid.
On the campus of Hawthorne College, Delta Sigma sorority sister Lindsey (Lucy Currey) is walking home after talking to her fellow sister Oona (Zoe Robins). Lindsey then gets a direct message from someone claiming to be Calvin Hawthorne, the school’s founder. She thinks she is being followed by a random guy, only to see that she is being stalked by a cloaked figure wearing a mask. Lindsey tries running to another house for help, but another masked man is there. As she pleads for her life, the cloaked figure grabs an icicle and stabs Lindsey in the chest, killing her. He then drags her body away.
In another sorority house, MKE, is Riley Stone (Imogen Poots), who lives with sisters Kris (Aleyse Shannon), Marti (Lily Donoghue), Jesse (Brittany O’Grady), Helena (Madeleine Adams), and Fran (Nathalie Morris). Riley goes to a class taught by Professor Gelson (Cary Elwes), who has come under fire for alleged sexism and knows there is a petition going around started by Kris (a heavy activist) to get him removed after he yelled at her for questioning why their reading curriculum didn’t include a diverse set of authors. Kris is also noted for having a bust of Calvin Hawthorne removed due to Hawthorne’s own noted personal history of misogyny.
Kris and Marti go with Riley to the coffee shop where she works. A shy nerdy guy named Landon (Caleb Eberhardt) who has a clear crush on Riley signs Kris’s petition after overhearing them talk. Riley is then unnerved when a frat boy from DKO named Phil (Ben Black) comes in, reminding the ladies about a frat event later that night, in which former president Brian Huntley (Ryan McIntyre) will be there. This troubles Riley since Brian raped her years earlier, and even though she came forward, he escaped punishment.
The sisters dress up for the event and go to the frat house. While the ladies practice their song, Riley wanders and finds a room where some frat brothers are performing a ritual with Hawthorne’s bust, which is leaking black liquid from its orifices. Riley sees a pledge have some of the liquid smeared on his head. She then goes to another room where she finds Phil and Helena about to have sex, but seeing that Helena is far too intoxicated, she prevents Phil from taking things further, and Riley sends Helena home in an Uber. Unfortunately for Riley, Helena was supposed to perform with Kris, Marti, and Jesse, so Riley must now take her place. The ladies go onstage to perform, but Riley freezes up when she sees Brian’s smug face looking at her. The other three help her before Riley gathers up the nerve to perform the song, which is meant to call out the frat’s rape culture. The women in there love it, but naturally, the frat brothers react with anger. As they head to another party, Landon joins them. Meanwhile, a cloaked figure stalks Helena in her room.
The next morning, Riley says bye to Fran, who is going away for the holiday break. After Riley goes to join the others in getting a Christmas tree, Fran is left alone at the sorority house where she is strangled with Christmas lights by a cloaked figure.
While out on the town, Riley gets a call from Helena’s mother, who says she never arrived home that day like she was supposed to. Riley then starts getting messages from the Hawthorne account that come off as threatening. She was also informed by Oona that Lindsey never got back home that night either. Riley goes to campus security for help to report that Helena is missing, but she is met with clear indifference. The officer escorts her to the DKO house to see if any of them have taken Helena, but nobody answers, so the cop leaves. Riley then runs into Gelson, accidentally dropping his papers. Among them, she finds a list of the ladies’ names, including her own. Gelson appears to intimidate Riley by noting that the college has sacrificed a lot to uphold certain traditions, and that they have come too far to have their names tarnished.
Riley runs back to the sorority house to confront Kris, who uploaded the full video of their performance from the night before, but she also recorded Riley saying “That’ll teach Brian not to rape another girl”. She thinks the video is what is causing the DKO frat to antagonize them. Although Kris is apologetic, she defends her stance by saying that they cannot let the men try to scare them. Marti’s boyfriend Nate (Simon Mead) interjects by saying that the ladies have been taking things too far and that they shouldn’t assume all men are out to get them. Marti argues with him and sends him out. Jesse, who left the room due to arguing, goes to look for Christmas lights. After plugging one set in, she is attacked by a cloaked figure.
The other three start getting more threatening messages until they find a figure with a bow and arrow shooting at them. Marti is grazed in the leg, and they run to hide. Riley goes to get a phone and keys to get them out, while Kris tends to Marti before going to find Jesse. Kris comes across Jesse tied up in Christmas lights with a glass shard in her face. Downstairs, Nate shows up again and finds Riley. She tries to explain the situation to him, but he gets shot in the face with an arrow. The figure attacks Riley, but she stabs him in the throat with her keys, killing her. Another figure attacks as Kris and Marti come downstairs. Marti threatens him with a hatchet, but the figure stabs her in the stomach. Riley and Kris run to the kitchen and are attacked, but they stab the figure to death. Riley notices there was no blood coming out of him. She unmasks him to find the pledge she saw the night before, realizing he was possessed. Just before Marti dies, she contacts the police. The same officer from earlier goes to Delta Sig to find Oona killing a figure, but another figure kills the officer.
Riley goes to DKO by herself to confront the frat. Kris drives to get help and picks up Oona and her sisters after learning they are also being attacked. Riley is found by Landon, who offers to help her. He goes into the frat house to break things to get the brothers’ attention. Riley makes her way inside and finds a room where Helena is tied up. She frees her, but is then knocked out by a cloaked figure, all while Helena gives a sinister smile.
Riley wakes up in the room with the bust where Landon has been brainwashed to be a pledge. Gelson, Brian, and other frat boys reveal themselves as part of a cult who has long upheld Hawthorne’s sexist ideals. They discovered the bust leaked the black liquid and contained the power to allow Hawthorne’s spirit to possess the pledges and give them inhuman strength. Helena was complicit and “obedient”, which allowed her to be spared. This doesn’t last long as they use Helena to demonstrate their power by having a pledge violently break her neck. Riley appears to give herself up and submit, but she just uses it as a distraction to grab her comb to attack Brian. Soon, Kris leads Oona and her sisters inside to fight the brothers. Brian attacks Riley, but she overpowers him and smashes his head hard enough to kill him. She then grabs the bust and destroys it, taking away the brothers’ powers. Kris then grabs a lantern and throws it at Gelson, setting him on fire. The ladies (and Landon) leave and lock the brothers inside as the house burns to the ground.