Jamie and Laurie take an Uber to the event. As they near the venue on a dark, deserted Brooklyn street, both women recognize the building, which they used to visit when it was a club called Cravin’, now renamed Serendipity. Jamie recalls its deliberately confusing layout—three levels threaded with dead-end hallways, hidden alcoves, and booths, useful for losing an unwanted date or finding a discreet corner with a wanted one.

Inside, Serendipity’s interior is saturated in deep red decor. At coat check, a frazzled attendant explains the regular cleaning crew was canceled, and the security guard is running late. She locks away their coats, phones, bags, and Laurie’s smartwatch, and Jamie takes the coat-check ticket for safekeeping. The attendant outlines the rules—no devices, no discussing jobs, and move on to the next date when the bell rings. The women are sent to the basement bar, while the men congregate on the mezzanine. As they descend, Jamie catches a glimpse of a shadowy figure leaning over the mezzanine railing, watching them. She dismisses her unease as pre-event anxiety and has a fleeting what’s-the-worst-that-could-happen thought.

The basement bar is wrapped in red velvet and flickering gas lamps. Host Marion distributes name tags and delivers a practiced speech encouraging the women to mingle. At the bar, a woman named Billie gives Jamie a pointed, disdainful look before walking away. Laurie and Jamie order espresso martinis and socialize, eventually meeting all the other women in the room: Colette, Dani, Jennifer, and Nia.

When Marion calls them to order, she explains the format: Women remain at assigned tables while the 10 men rotate every 10 minutes, signaled by a bell. There is a 15-minute break at the halfway point, and Marion will follow up the next day with mutual matches. She goes upstairs to retrieve the men. Jamie and Laurie, more focused on where to eat afterward, joke about their dating strategies.

The first three dates yield little. Drew pays more attention to Jamie’s chest than her words; Stu gives her the silent treatment after she accidentally calls him Drew; and Lee spends his entire 10 minutes talking about Nia. Jamie agrees to help him strategize afterward.

Her fourth date, John, is a marked improvement—shy, attentive, and clearly listening to the other women he’s met. Jamie impresses him by reciting dialogue from While You Were Sleeping from memory. When the bell rings, he looks reluctant to leave and asks her for a drink after the event. Jamie agrees.

John’s replacement is Wes—physically striking in a way that doesn’t fit Jamie’s usual type. After a few seconds of eye contact and a slight smile, she mentally marks him as a yes before he has said a word. Wes opens by asking what makes her happy and seems genuinely curious. Jamie answers honestly—movies—and quickly breaks the no-work rule to mention her dissertation. Wes says he likes happy endings, especially when the underdog wins. Their conversation flows easily. She tells him that she likes Taylor Swift—a topic that she has found herself discussing with each of her dates at the event. Wes tells her that his favorite films include the romantic comedy Miss Congeniality, which delights Jamie. When he mentions that he arrived with a what’s-the-worst-that-could-happen mindset, Jamie blurts out an answer: “We could get murdered” (35). Wes’s expression immediately turns grave.

Wes remains withdrawn after Jamie’s murder comment. She tries to explain herself by referencing true-crime podcasts and the behavior of notable serial killers, which only makes Wes more distant. When the bell rings, Wes leaves quickly and avoids making eye contact during the break. John appears absorbed in conversation with Jennifer, so Jamie believes that she has lost both of these promising connections. Her sixth, seventh, and eighth dates pass without incident.

Date nine is Curtis, who is arrogant, crude, and convinced that the women around him are the problem. When he makes a crass remark about Jamie’s dress, she tells him plainly that if he thinks every woman he meets is difficult, then he’s likely the problem.

Before Curtis can respond, the lights cut out. In the darkness, Jamie hears confusion, breaking glass, and an unfamiliar wet, gargling sound she cannot immediately identify. When the lights return, Curtis sits motionless across from her with a deep gash across his throat. Jamie screams.

The room erupts into panic. Rather than joining the stampede toward the single narrow exit, Jamie stays put, guided by her extensive knowledge of slasher films. The lights cut out again. She hides under her table as more screaming and slicing sounds fill the room. Silence falls again, followed by footsteps pounding on the floor above.

When the lights return, Jamie scans the room and finds Laurie crouching unharmed under her own table. They signal each other to stay put. Jamie grabs a nearby broken Kahlúa bottle as a weapon before emerging. Four people are dead (Curtis, both bartenders, and Marion), and the eight survivors include herself, Laurie, Wes, John, Stu, Colette, Dani, and a man whom Jamie identifies from his name tag as Campbell.

A brief, sharp scream sounds from the floor above, followed by a thud. The killer has moved upstairs and is still active.

Wes asks if anyone is hurt; no one is. John states they need to leave the basement. Using her memory of the building from its days as Cravin’, Jamie confirms there is no exit downstairs and suggests using the second staircase to reach the ground floor and cross to the front entrance. The survivors arm themselves with broken bottles and move upstairs single file, with Wes leading and John at the rear.

The ground floor is undisturbed, but the heavy front doors will not open. John finds a keypad near the coat check that controls the lock, but it requires a code. Jamie concludes the killer has trapped them and must be one of the daters. In the coat check room, Colette finds the attendant dead with a meat cleaver in her forehead. The lockbox holding everyone’s phones is missing, along with the attendant’s phone and iPad. Jamie finds the lockbox key on the desk, but no box. All communication with the outside world has been cut off. Stu suggests they split up to find another exit.

Jamie immediately rejects splitting up, citing the killer’s efficiency in darkness and the impossibility of communicating between separated parties. Wes backs her. Stu accuses Wes of pandering to Jamie, and the two men face off until Campbell steps between them. Laurie offers a compromise: two groups of four, each searching one side of the same floor, reuniting on the dance floor in 30 minutes. Campbell and Stu, whose analog watches were not confiscated, serve as timekeepers. The groups form: Wes, Campbell, Laurie, and Jamie together; John, Stu, Colette, and Dani on the other side.

Stu, who feels he had a successful date with Laurie, is displeased that she chooses Jamie’s group. Before separating, John checks in with Jamie, making sure she is all right after her confrontation with Curtis just before his death. Wes observes their exchange before looking away. The two groups head in opposite directions.

Jamie’s group moves cautiously along the left side of the ground floor. Partway through a curtained hallway, Jamie catches her heel in the carpet and falls into a booth. When she stands, her arms are covered in red glitter left by the hasty cleaning crew. She removes her heels, laces them together as a blunt weapon, and continues barefoot. Wes teases her about the resulting height difference, and the exchange turns flirtatious. Laurie and Jamie conduct an entire silent conversation through facial expressions about it while Wes checks the next alcove.

At the third alcove, a curtain moves more than the others. Despite Wes’s objections, Jamie positions herself beside him before he pulls it back. Inside is Billie—alive, hostile, and unimpressed by the broken bottle pointed at her. She explains that when the doors wouldn’t open, she ran and hid after hearing the scream and has blood spray on her sweater from the initial chaos. When told the death toll, she shrugs and makes a grim comment about the night not being over.

Two alcoves further on, the group finds Jennifer hiding behind a curtain. She joins them, bringing the group to six. They reach a three-way corridor intersection with no clear sense of the layout, and Campbell admits he forgot to note the time they set out. Laurie establishes 11 PM as the new rendezvous deadline.

They proceed straight and soon spot a dark red stain spreading from around a corner. Jamie notes that walking toward a growing pool of blood is generally unwise, but Wes argues that an exit may lie just beyond it. Against his protests, Jamie insists on going with him rather than letting him check alone. She swaps her larger broken bottle for Laurie’s smaller one, leaving the group better armed, and Wes instructs the others to stay against the wall and run if anything happens.

Around the corner, they find Drew and a red-haired woman dead, each with matching puncture wounds to the throat and rose petals scattered around them. The petals continue down the corridor in a deliberate trail. Wes pulls Jamie close behind him as they follow it, then asks whether she saw the earlier news report about the Brooklyn Serial Killer. Jamie connects the rose-petal detail to that broadcast, suggesting that the killer in the club and the Brooklyn Serial Killer are the same person.