Stu collapses and dies. Heart Eyes retrieves the ax and locks eyes with Jamie and Wes. Jamie lets Wes pull slightly ahead as they run into the debris-filled back corridor. Jamie cuts her foot on broken glass, and Wes crashes hard into a barricade of stacked furniture, injuring his ribs. They find a speed-dater named Campbell pinned to the wall by multiple knives, hands bound around a bouquet of roses—the staged offering meant for Jamie that Stu described earlier. Wes pulls her away, and they locate a smoke detector near the mezzanine.

As Wes ignites the lighter, they hear approaching footsteps, and Jennifer appears with Billie behind her. Jennifer announces that Billie has found an exit. When Jennifer suggests they still trigger the alarm, Billie stops her, saying the night isn’t over. She draws a switchblade and slashes Jennifer’s throat. Jennifer dies almost instantly. Billie produces the pink knitted Heart Eyes mask from her pocket and taunts Jamie that the night is going just as expected.

Jamie absorbs the revelation that Billie is Heart Eyes. Armed with a switchblade and a kitchen knife, Billie confirms her role, mocks Wes for concealing that he is a police officer, and explains she cannot kill Jamie yet because the night must fully play out first. When Wes lunges at her, she slashes him across the chest and drops him to his knees. Jamie swings the wooden stake and breaks Billie’s nose. The force sends Billie stumbling into a guardrail set too low to break her fall, and she plummets to the dance floor below, dying on impact.

Jamie bandages Wes’s chest wound using Jennifer’s first aid kit. As she works, a critical inconsistency surfaces: The first time Heart Eyes appeared, Billie was with Wes in the basement and could not have committed that kill. Jamie realizes they are dealing with two killers.

Jamie’s suspicion shifts to Wes. Reviewing his absences and the timing of each attack, she backs away from him and refuses his reassurances. Convinced that trusting a love interest is exactly the kind of fatal mistake the women in slasher films make, she runs. Alone near a staircase, she forces herself to breathe, thinks of Laurie, and reviews the match cards she has kept in her bra, mentally accounting for the night’s victims and those still missing. Her panic gradually clears: Wes was standing beside her when Heart Eyes buried the ax in Stu’s skull, and the figure was physically larger than Billie. Her instincts insist Wes is innocent, though she cannot yet identify the second killer. As she reaches this conclusion, John—whom they’d found dead in the bathroom—appears at the bottom of the nearby staircase, very much alive.

John ascends the staircase toward Jamie, and she realizes that he had faked his earlier wounds. He cups her face and kisses her, and Jamie realizes that he’s killed all these people to get to her. John delivers a calm, methodical confession: He spotted her the moment she entered the club, decided she was his destined partner, and engineered the entire night as a test of their compatibility. He admits to killing five previous women who failed to meet his expectations and explains that Billie—a woman he met at a cooking class who later followed him home—agreed to help him in exchange for his company. He invites Jamie to have a drink. She stalls, feigning overwhelm, and bolts the moment he leans in for a second kiss.

Jamie runs through the corridor and spots a flashlight ahead, leading her to Wes. She tells him John is the second killer. Wes reveals he’s found six other previous unaccounted-for survivors, including Lee and Nia, hidden in a locked room with a tampered control panel and one working security camera trained on the dance floor. Remembering the club’s rooftop smoking area and fire escape from a prior visit, Jamie realizes the furniture barricade must be hiding that door. They head back toward the survivors with a plan.

Jamie proposes that she alone lure John to the dance floor while Wes and the survivors dismantle the furniture barricade to access the rooftop exit. Wes objects on both professional and personal grounds but concedes when Jamie points out that he is the only one capable of leading the others out safely. They say a brief, tense goodbye, and Jamie slips out alone. She collects the rose bouquet from Campbell’s body, takes one of the knives pinning him to the wall, hides it among the stems, and descends to the dance floor, calling John’s name.

John’s playlist activates Taylor Swift’s “Love Story,” and the disco ball begins spinning as Jamie waits on the dance floor holding the roses. John appears on the mezzanine, descends, and approaches. Jamie keeps his focus on her, deliberately provoking his jealousy by disclosing her encounters with Wes. As John moves toward her, the sprinkler system activates—triggered by the survivors who have cleared the rooftop exit—and the fire alarm sounds. John delivers a grand declaration of love, demanding Jamie agree to his version of their love story. Unwilling to speak the words he wants, Jamie drives the knife hidden in the roses up beneath his ribs, killing him.

Police and paramedics breach the club’s entrance. Jamie locates Laurie wrapped in an emergency blanket, behind a police barricade. Officers briefly restrain Jamie before a senior officer orders them to release her, and she and Laurie embrace. Medics treat Jamie’s injuries while Captain Strode takes her statement. Before the interview concludes, Wes arrives, having led the six survivors to safety via the roof. After he and Jamie reunite, she gives the captain a full account—confirming she killed John, that he admitted to prior murders, and that Billie was his accomplice.

Eight months later, Jamie, Laurie, and Wes share a larger, more secure New York apartment. Jamie attends regular therapy, finishes her dissertation, and begins teaching an Introduction to Film Studies course. Laurie is developing a documentary about the events at the club. Wes is back on active duty under Captain Strode. All three continue working through residual trauma by supporting one another. Jamie and Wes are in a committed relationship, and Jamie closes by reflecting that their survival is due to the choices each of them made, rather than fate or formula.