The confrontation moves to the kitchen, where Jodie gains the upper hand by retrieving Roy’s shotgun. Jodie reveals she loaded the gun before giving the remaining cartridges to Marie. She forces the housekeeper into a chair and ties her wrists and ankles with kitchen twine. Under interrogation, Marie confesses she hated Deborah. She admits to putting a sleep aid in Jodie and Deborah’s nightly tea. While they were unconscious, she injected their faces with corticosteroids and other fillers to cause disfigurement, driven by her obsessive love for Roy and jealousy of his wives.

Marie recounts how she and Roy drugged and underfed Deborah to keep her “weak.” However, somehow Deborah escaped the locked room while Roy was at work and Marie was out shopping. Deborah found Marie’s medical supplies and employment file, and called the clinic where Marie used to work, learning she had been fired. She then confronted Marie, who retrieved the shotgun, and forced Deborah’s hands onto the weapon before shooting her in the face, ensuring gunpowder residue on Deborah’s hands. She then deleted security footage of her return to the house before “discovering” the body. Smugly, Marie tells Jodie that Roy will believe her over Jodie and that Jodie should untie her and leave if she wants to avoid prison.

Jodie calmly makes a peanut butter and jelly sandwich while telling a defiant Marie that her real name is not Jodie. Marie’s confidence crumbles as Jodie reveals she is Joanne, Deborah’s sister. Jodie explains that she came to the house believing Roy was the killer and that Marie would have gotten away with the murder if she had not confessed.

Ignoring Marie’s pleas, Jodie takes an expensive Steuben crystal glass, shatters it in a tea towel, and sprinkles the shards into the sandwich. She then tries to force-feed the glass-laced sandwich to a screaming Marie. Just as she pinches Marie’s nose shut, they hear the front door open and Roy calling Jodie’s name.

Roy enters the kitchen and is horrified to find Marie tied to a chair in Deborah’s wedding dress, with Jodie holding a shotgun. As Marie screams for help, Jodie aims the rifle at Roy. She confronts Roy about locking Deborah in the upstairs room, which he admits to, claiming he was trying to help her.

Jodie reveals that Marie was the one disfiguring Deborah. Roy, finally understanding, turns on Marie in fury. He then tries to call the police, but Jodie knocks the phone from his hand. As she presses the gun against Marie’s mouth, Roy lunges for the weapon. During the struggle, Jodie pulls the trigger, killing Marie. She then releases the rifle so Roy is left holding it, and runs outside screaming for help.

At the police station, Jodie is given a change of clothes and questioned by Detectives Bates and Marcos. She calmly tells them her true relationship to Deborah. When they bring up her prior manslaughter conviction, she insists she wasn’t driving during the incident but states it’s irrelevant. Jodie then begins laying out her version of events, admitting she married Roy solely to prove he had systematically abused, isolated, and killed her sister.

Continuing her police interview, Jodie constructs a false narrative. She presents evidence, including Roy’s appointment book and Veronica’s love letter. She describes the video of Roy tormenting a locked-up Deborah, which she claims Marie found and showed to her.

Jodie tells the detectives that she and Marie, united in their love for Deborah, planned to go to the police. She invents a story that Marie, fearing the video wasn't enough proof, devised a "crazy idea" to wear Deborah's wedding dress to scare Roy into a confession. According to Jodie's story, Roy came home early, flew into a rage, tied Marie to a chair, and confessed to everything before wrestling the gun from Jodie and shooting Marie. She tearfully claims she did everything she could to save Marie and ran for her life. The detectives inform her that Dr. Davies's version of events is completely different, stating that she was the one who shot Marie. Jodie dismisses this as the lie of a guilty man, portraying herself as a victim who was trying to avenge her sister alongside her friend, Marie. Detective Bates, escorts her out, telling her she cannot return to the house.

While Roy remains in prison, Jodie moves back to her old studio apartment, waiting for the trial. Detective Bates visits and informs her that while Roy will be held for Marie’s murder, proving he killed Deborah will be extremely difficult without a witness. 

Recalling something in Mikey’s eyes when she asked him whether he had seen Deborah the day she died, Jodie visits Meredith’s housekeeper, Dolores, and asks to talk to her deaf son.

Alone with Mikey, Jodie communicates with him using his tablet. He confirms he was in the Davies’s house on the day Deborah died, having used the back-door code she had given him. He writes that he saw Marie in the house just minutes before Deborah’s murder.

Realizing this testimony could upend her case against Roy, Jodie tells him about the horrific abuse Roy inflicted on Deborah. She writes that she is afraid Roy will get away with it and asks Mikey to tell the police he wasn’t there that day. Mikey refuses, insisting he is not a liar.

Two years later, Roy is tried for the murders of Deborah, Veronica, and Marie. Jodie gives her rehearsed, tearful testimony, repeating the story that she and Marie were allies and that Roy killed Marie in a rage. When the prosecution calls Mikey to the stand, Jodie panics, fearing his testimony will destroy her case. However, when asked if he saw the person who entered the house that day, Mikey points directly at Roy. His testimony seals Roy’s fate.

A year after the trial, Roy has been convicted of Deborah’s and Marie’s murders and is serving a life sentence. Jodie is thriving, having started a successful catering business with her friend Dolores. She has also bought a beautiful home of her own, decorated exactly to her taste, and stocked with the miniature soaps she loves. 

One day, Detective Bates visits Jodie. He reveals that while closing old files before his retirement, he discovered a connection. The man Jodie was convicted of killing in a car accident years ago was the same man her sister, Deborah, had filed an assault complaint against.

Bates produces a photograph from the Border Patrol checkpoint on I-8. The photo proves that Jodie was driving while her boyfriend, Beau, was in the passenger seat. Bates accuses her of intentionally running over her sister’s abusive ex-boyfriend. Jodie does not deny it, recalling how she accelerated when she recognized him at the roadside. Bates reveals that Deborah’s boyfriend went on to rape and assault several other women before Jodie killed him. Jodie concludes that she “did the world a favor” (343), but the detective remains stern, pointing out that vigilante justice is illegal.

Jodie panics at the prospect of her new “family,” Dolores and Mikey, discovering she is a killer. She persuades Bates to have some of her homemade cake. In the kitchen, Jodie secretly smashes a glass in a tea towel and prepares to place slivers of glass in the detective’s cake. As she does so, she hears Deborah’s voice urging her not to do it and changes her mind. Resigning herself to her fate, Jodie returns to the living room to see Bates ripping up the incriminating photograph and throwing it in the fireplace, destroying the only evidence of her crime. He agrees that Jodie “did the world a favor” (345). Furthermore, the double jeopardy law prevents any retrial.