On the picturesque grounds of Hawthorne College, Lindsey (Lucy Currey), a member of the Delta Sigma sorority, embarks on a peaceful stroll home after a heartfelt chat with her sister Oona (Zoe Robins). However, her tranquility is abruptly shattered when she receives a distressing direct message seemingly from Calvin Hawthorne. Lindsey's discomfort intensifies as she detects a hooded figure lurking ominously in the shadows. In a frantic bid for safety, she races to another house, only to encounter another masked assailant. In a harrowing turn of events, her pleas for mercy are met with horrific violence as the cloaked figure drives an icicle into her chest, taking her life and dragging her body away without a second thought.
Meanwhile, inside a sorority house, Riley Stone (Imogen Poots) navigates daily life alongside her sorority sisters Kris (Aleyse Shannon), Marti (Lily Donoghue), Jesse (Brittany O'Grady), Helena (Madeleine Adams), and Fran (Nathalie Morris). As she juggles academics, Riley attends a class led by the beleaguered Professor Gelson ([Cary Elwes]), who is currently under fire for alleged sexism. Activist Kris leads a petition aimed at ousting Gelson after his public reprimand of her for challenging the lack of diversity in the reading curriculum. The petition, while gaining traction, also brings scrutiny upon Kris, especially after she removes a bust of Calvin Hawthorne from campus, acknowledging his tarnished legacy of misogyny.
During a visit to a coffee shop where she works, Riley conjoins with her friends along with the shy and infatuated Landon (Caleb Eberhardt). After overhearing the conversation, he hesitantly signs Kris's petition. The atmosphere thickens when Phil (Ben Black), a fraternity brother from DKO, arrives to promote an event featuring former president Brian Huntley ([Ryan McIntyre]). Riley’s discomfort escalates as she recalls a traumatic encounter with Brian, who evaded consequences despite her brave efforts to expose him.
As nighttime descends, the sisters adorn themselves in elegant attire to perform a song at the frat house. Riley's curiosity leads her to uncover an ominous ritual taking place in an upstairs room. A bust of Hawthorne is awash in a dark, viscous liquid, captivating the attention of fraternity brothers. Riley's unease heightens as she observes a pledge having the ominous substance smeared onto his forehead, and she quickly vacates the room. Upon her exit, she interrupts an intimate moment between Phil and Helena, ensuring Helena’s safety by sending her home, unknowingly triggering severe repercussions.
With Helena missing from their performance, Riley steps in alongside Kris, Marti, and Jesse. As they take the stage, Riley succumbs to her nerves, locking eyes with Brian, whose smirk seems to penetrate her very being. Rallying around her, the ladies support her in delivering a powerful song aimed at exposing the toxicity within fraternity culture. The performance resonates with the women present but incites fury among the frat brothers.
As the festivities progress, Landon rejoins the group, leading them to another party. Amidst the celebration, a foreboding dark figure hones in on Helena as she prepares for bed.
The next morning, Riley bids farewell to Fran, who is preparing to leave for the holiday season. As Riley and her friends venture to gather a Christmas tree, Fran remains behind, unwittingly becoming prey to a sinister attack by a cloaked figure armed with Christmas lights.
As the day unfolds, Riley receives alarming news from Helena’s mother, revealing her daughter never returned after the previous night's party. The situation escalates when Riley begins receiving ominous messages from the Hawthorne account, each more terrifying than the last. Oona further shocks Riley with the revelation that Lindsey also went missing that night.
In her search for answers, Riley turns to campus security but is met with indifference. An officer leads her to the DKO house, where she anticipates finding answers only to discover a locked door and oblivious residents. In her frustration, she accidentally drops Gelson's papers, revealing a list that ominously includes her name.
Upon Gelson's arrival, his menacing aura hints at the college's readiness to protect its reputation by sacrificing the truth. Realizing the sisters' names are to remain untarnished, Riley rushes back to the sorority house, overwhelmed by the fallout from Kris’s provocative video. Despite Kris's remorse, she stands firm, insisting on not allowing the men to dictate their lives.
As tensions mount, Marty’s boyfriend Nate (Simon Mead) warns the sisters against viewing all men as adversaries, inciting conflict between him and Marti. This leads to Nate storming out, while Jesse seeks comfort among Christmas lights, only to be ambushed by an unknown attacker.
In a desperate struggle for survival, the sisters soon receive threatening messages culminating in a confrontation with a bowman whose arrow narrowly grazes Marti's leg. Seizing the moment, Riley grabs their keys and phone, while Kris tends to Marti's injury.
In the ensuing chaos, Riley is horrified to see Nate return, only to be struck by an arrow. As they fight the attacker, Riley manages to kill him with her keys. Yet, another figure emerges from the darkness, forcing Kris and Marti into a fierce battle for survival.
Upon assessing the aftermath, Riley is struck by the bloodless body of the assailant, which leads to a chilling revelation as the mask is removed to reveal the pledge she saw the previous night, now a conduit for evil. As hope dwindles, Marti courageously reaches out to summon help.
Simultaneously, Officer Jenkins, an acquaintance from earlier, is ambushed by Oona, who dispatches yet another figure. His demise heralds a night drenched in blood, leaving none safe.
Resolute, Riley ventures alone into DKO territory, driven by determination to confront the fraternity. Kris, meanwhile, accelerates to mobilize Oona and their sisters for reinforcements. Unbeknownst to Riley, she is confronted by Landon, who chooses to aid her, making a bold move into the frat house to create a distraction for Riley’s covert approach.
As she cautiously navigates the darkened halls of the fraternity, Riley stumbles upon a room containing Helena, bound and at the mercy of a sinister force. Landon assists in her rescue, but their victory is fleeting as a hooded figure strikes Riley with unforgiving swiftness, unveiling Helena's eerie calmness that hints at her own involvement with the fraternity's dark plans.
Riley regains consciousness in a dimly lit chamber, surrounded by the unsettling silence of Landon’s brainwashed pledge brothers. The sinister alliance of Gelson, Brian, and their cohorts lays bare their malevolent agenda linked to Hawthorne's legacy, revealing that the bust has been used to grant the pledges inhumane power. In a dramatic twist, Helena's deception unravels as she demonstrates her "allegiance" by initiating a brutal execution at the hands of one of the possessed frat boys.
Seizing the opportunity to feign compliance, Riley cleverly plays along while plotting her next move. Just as chaos erupts, Kris and Oona burst in, giving Riley the opening to unleash her fury on Brian and quickly subduing him with a decisive strike.
With the fraternity boys left leaderless, Riley shatters the bust, dismantling their dark powers. Kris, Oona, and the sisters band together to confront the remaining brothers while they flee, sealing the house behind them as it ignites in flames, engulfing the malevolent spirits within its walls.
