Elsie, Margot, and Beverley arrive at the home of their prime suspect’s wife, Sharon Farrer. Beverley had previously shown them Cheryl’s bracelet, which Sharon found near the brake pedal of her husband Hank’s truck and presented to Beverly when they met at the diner. Sharon, fearing Hank’s threats, had begged them not to involve the police.

Sharon answers the door in a robe, visibly tired. She has a black eye. On the kitchen table sits a Polaroid Automatic 100 camera, a recent gift to her teenage son Peter, who hopes to attend film school. Her young daughter, Jessica, plays with troll dolls while Peter lies in his darkened bedroom. Elsie notes that Peter’s hand is bandaged.

Over coffee, Elsie asks whether Hank is violent with the children. Sharon implies that Peter has intervened on her behalf. She insists Hank would never hurt Jessica, and Elsie quietly notes that the pet name he uses for his daughter matches a term from a news report about Cheryl Herrera’s father. Sharon describes Hank’s sudden acts of rage, confirms he has been working long hours restoring police cars, and admits she has never heard the victims’ names. She also concedes that Hank prefers younger women and likely hires sex workers, having found motel receipts in his clothes. Margot proposes they visit the garage; Sharon provides a flyer. Elsie’s last question is to ask for Hank’s license plate number.

Elsie races home feeling on the verge of a breakthrough. The sensation triggers memories of discovering Albert’s crimes, and of a letter from her dying father that quoted Shakespeare on carnage and death, which she now understands as an oblique apology influenced by his trauma of war.

Back in the present, she locates the copied pages from the sex workers’ Beware Book and searches for the license plate number Sharon provided. She finds a match for Hank Farrer’s vehicle, with notes describing sexual violence. Hands trembling, she reaches for the phone.

After the others leave, Beverley reflects on the case: the evidence against Hank is accumulating, though not yet conclusive. Restless, she retrieves an old sentimental card from Henry, reads his declaration of love, then forces herself to put it away, separating the man she married from the killer he became.

Unable to sleep, she takes pills and washes them down with whiskey. She wakes later in darkness to a banging sound and realizes she forgot to barricade her front door. It stands open. She sprints upstairs to find Benjamin’s bed empty, grabs her daughter Audrey, and rushes into the street. Christopher Appleton, drawn outside by the commotion, denies knowing anything. Beverley runs through dark streets until she spots Benjamin standing motionless in the road, staring toward a nearby house. She pulls him close, follows his gaze to the front porch, and sees a body hanging from a hook.

Beverley waits inside the Gunn house with both children for the police to examine the body of the new murder victim, Sarah Gunn. She had persuaded Sarah’s father not to touch the body, noting that Sarah was dressed in a trench coat identical to one worn by murder victim Diane Howard Murray, and that the staging of the corpse connects to a threatening note found in Ventura.

Roger and Bale arrive. Beverley gets Roger alone and tells him she has a suspect: Hank Farrer. Roger dismisses her, insisting she should stay home. Beverley pushes back, accusing the department of prioritizing Chief Cornwell’s career over the investigation. Roger admits that Cornwell’s influence forces him to follow protocol. Unmoved, Beverley spells out the name Hank Farrer, tells Roger the responsibility is now his, and resolves privately to press on herself.

The following evening, Margot arrives at her dilapidated apartment and eats crackers alone, distraught over how her life has changed over the years. Her thoughts return to Stephen. Having already witnessed him at Silver Lake Lookout, she followed him one morning to Riverhead, where she watched him enter a phone booth with a scarf over his face and deposit an envelope in a nearby mailbox. Determined to see what he had sent, she retrieved a baseball bat from her car and beat the mailbox until she could force her arm inside. She pulled out handfuls of mail and found a small manila envelope addressed to the editor of the New York Times. Inside was an unsigned letter confessing to the Silver Lake Lookout killings and additional murders. This was the definitive proof she needed of his crimes, which she later handed over to authorities.

Returning to the present, she grabs her purse and coat and goes out.

That same night, Beverley and Elsie stake out Hank Farrer’s garage from Elsie’s pink Buick. A taxi drops Margot off; she climbs in, having abandoned her date. Beverley mentions they earlier saw Peter Farrer drive out, suggesting Hank’s son also works at the garage.

After an hour of inaction, Margot questions whether Hank is their man. Exhausted and off-guard, Beverley accidentally reveals that she visited Henry at San Quentin, violating the pact all three women made to cut off contact with their former husbands. Elsie is stunned; Margot is furious. The argument escalates: Margot accuses Beverley of being controlled by Henry; Beverley fires back that Margot is in denial about Stephen’s death; Margot reveals that Beverley keeps Henry’s photograph on her fridge; Beverley responds with a crude remark about Margot’s sex life. Margot gets out and slams the door.

Almost immediately, Hank appears at the garage entrance, spots the car, and strides toward them brandishing a gun. Elsie stalls the ignition repeatedly before the engine catches and she accelerates toward Margot, who dives into the back seat. They screech away, leaving an armed and furious Hank in the road.

At a morning news meeting at the Signal, editor Paul Hunter announces a fifth victim: Kate McKenzie, a woman stabbed in her own bathroom. Elsie immediately calculates that the murder occurred around midnight, which was when she and the others were watching Hank at his garage. This rules Hank out as the murderer. After a terse exchange with senior reporter Robert Heston, who mocks her questions, Elsie alerts Hunter to the scratches on Heston’s hands and arms. Hunter dismisses the suspicion, attributing them to his wife’s new cat. Elsie then pitches a piece on the victims as individuals rather than statistics; Hunter reluctantly agrees to 500 words for the domestic column.

Later, at Beverley’s house, Elsie delivers the news about Hank’s alibi. The news leaves Beverley distraught. Convinced the group’s misdirected focus cost another woman her life, she confesses something she has never told anyone: She believes she could have stopped Henry. While pregnant with Audrey, she watched from a darkened kitchen as Henry returned home at three o’clock in the morning and stripped off his clothes in the driveway, tossing them into a neighbor’s trash. Assuming he was having an affair, she said nothing. The next morning she found the clothes soaked in blood, told herself it was from a bar fight, and never raised the issue with him. Henry killed two more women after that night.

Elsie refuses to let Beverley carry the blame. She tells her that they cannot answer every question, that some of the pain will never fully leave them, and that the only way forward is to accept it and keep going. She promises they will regroup and outsmart the killer.

Several weeks pass in a daze for Beverley. The argument with Margot remains unresolved. She calls Sharon Farrer to say they are no longer looking into Hank; Sharon sounds relieved but quietly disappointed, knowing Hank will remain free. Beverley continues building her scrapbook as the press reports on a newly formed police task force pursuing the Central Valley Slaughterer.

Beverley resumes her affair with Roger. One evening in bed, Roger tells her his team has a new suspect in Ventura with a prior kidnapping conviction. When Beverley suggests her neighbor Christopher Appleton should be investigated, Roger reveals he has already kept Appleton under surveillance for two weeks; the man is simply a recluse. He tells her dismissively that a “housewife” cannot solve a murder.

As Roger leaves, Beverley returns papers she found in his coat pocket. After he goes, she spots a scrap on the floor. It is a Polaroid photograph labeled McKENZIE CRIME SCENE. In the grainy image she recognizes an object lying in the grass that she has seen before.

The next morning, Beverley rushes to the Signal office and pulls Elsie outside. She identifies the camera visible in the crime scene photograph by its distinctive checked strap. It is the same Polaroid Automatic 100 that sat on the Farrers’ kitchen table. When Elsie objects that Hank has been ruled out, Beverley clarifies she is not talking about Hank. She asks whose camera it is. Elsie takes a moment, then understands: It belongs to Peter Farrer.

Beverley tries repeatedly to reach Roger by phone but gets no answer. She calls the precinct under her former name and asks for Detective Greaves, but the call is cut off. Her only remaining option is to go to Roger’s home and risk meeting his wife.

She drives to Roger’s modest suburban house and knocks. There is no answer. Peering through a window, she sees an orderly, undisturbed interior and briefly fears Roger may have confronted Peter Farrer alone and been harmed.

Unable to wait, she drives away and resolves that she, Elsie, and Margot should go directly to Sharon and tell her the truth about her son.