Jane and Dexter meet in Covent Garden and drink wine. Jane expresses her horror over the revelations about Jasper’s “Patch the Clown” persona and his pattern of sexually harassing young women in his costume. She becomes emotional, thanking Dexter for his support and realizing that investigating the Black family’s life is forcing her to confront the trauma of her own childhood living with addicts. She compares her cheerful public persona to a mask, like Jasper’s. Dexter comforts her, suggesting she sell her large, isolated house, move to London, and start a private investigation agency.

Jane wakes early, anxious about her plan to report her findings to the police. Her thoughts are a mix of the case’s dark details and her own existential worries. She receives an unexpected text message from Stuart, inviting her to Thornwood to talk before she goes to the police. Though she fears it could be a trap, she agrees, seeing it as an important opportunity. She messages Stuart back, warning him that she has told several people her whereabouts, including Dexter and Tobias, who will call the police if he doesn’t hear from her by 9 a.m. She also packs two knives for protection. On her way, Jane stops at the home of the Blacks’ neighbor, Spencer, and asks him to check on her if she isn’t back in a few hours. Spencer agrees, and Jane proceeds to Thornwood, where Stuart lets her inside.

Inside the neglected house, Stuart makes tea for Jane and a bacon sandwich for himself. Jane notices fresh scratches on the inside of his wrist. Stuart tells her there is something she needs to hear directly “from the horse’s mouth” (323). He calls out toward the hallway, and a young woman with bleached blonde hair walks into the kitchen. She introduces herself to Jane as Daisy.

Daisy recounts her story, explaining that her obsession began during the COVID-19 lockdown when a police officer showed her a photo of Claire during their search of the house. She instantly recognized a family resemblance and knew that Jessamine was not her real mother. She dropped out of school and spent her days in isolation, researching Claire online and writing elaborate stories about her to post in internet forums. Her fixation amplified her resentment toward the alcoholic and abusive Jessamine. About a year ago, Daisy discovered an old photograph of her grandfather Allen, Jessamine, and a young boy with a clown’s mask on his lap. The back was inscribed with “The Last One of Us” (329). She concluded the boy in the photo was her mysterious uncle, Jasper, and became convinced he held the key to learning the truth about her mother.

Daisy continues her story, explaining that she tracked Jasper to a circus in Dorset. She rented a nearby studio and brought Hugo for companionship. After watching Jasper’s sad clown act and observing his lonely life for a few days, she confronted him at his trailer. When he tried to refuse to speak with her, she threatened to reveal his location to the police. Jasper relented and agreed to meet her the next day, later sending her map coordinates for a location in the woods.

In the woods, Jasper confirmed that Claire was Daisy’s mother but claimed he didn’t know what happened to her, repeatedly insisting Daisy ask Annie. When Daisy pressed him, Jasper became extremely agitated, confessing that there had been a terrible fight and that he had run away in fear. As he grew more distraught, he tried to flee. Daisy grabbed him to stop him, and they both fell. Jasper then got on top of her and began to strangle her, kicking Hugo away when the dog tried to intervene. Daisy managed to knee him in the groin, break free, and escape. Back in the present, Daisy tells Jane she couldn’t find Hugo and called Stuart for help. Stuart and Daisy then lead a tense Jane to the outhouse and unlock it, revealing Annie’s dead body.

Jane is horrified by the sight of Annie’s body. Stuart explains this is why they couldn’t involve the police. Daisy confesses to pushing Annie down the stairs the previous week during a heated argument about Claire and begs Jane not to report it. Jane, clutching the knife in her bag for safety, learns that Jessamine is unaware of her mother’s death. She insists they must tell Jessamine immediately, hoping the truth might finally compel her to speak honestly about the past.

In Jessamine’s squalid bedroom, Stuart attempts to explain what has happened, but Jessamine only frantically demands a drink. He finally tells her that Annie is dead, explaining that she fell during a struggle with Daisy. Upon hearing the news, Jessamine’s demeanor changes completely, and a spark of life returns to her eyes. After confirming her mother is truly dead, she urgently instructs Stuart to call the police, tells him to say that she was the one who pushed Annie, and to “let [her] tell them why” (346).

When the police arrive, Jessamine tells them she pushed Annie and declares that her parents were murderers, calling Thornwood a “house of fucking horrors” (348). In Annie’s study, investigators discover a trapdoor leading to a secret basement containing the remains of Allen and seven young women: Naomi de Santo, Jody Pinkerton, Susana Perez, Elena Iannou, Jade Paris-Smith, Charaya Kim, and Claire Connolly. Jessamine tells police that Annie killed Claire and Allen in a jealous rage, knowing he was in love with Claire, and forced Jessamine to raise Claire’s baby, Daisy. She claims she pushed Annie when she saw her move to slap Daisy. Jane returns home, shaken, but finds herself deeply suspicious of the relief she saw in Jessamine’s eyes and does not trust her story.

While a police officer supervises him, Stuart packs his belongings, moving through Thornwood in a state of numb horror. He feels culpable for having lived for a decade in the house, unaware of the bodies buried beneath the floorboards. As he listens to the sounds of the excavation team in the basement, he collects Hugo and leaves the property, certain he will never return to the dark house.

A few days later, Dexter visits Jane at her country estate. They discuss the case, and Jane expresses her belief that Jasper, still missing, has likely died by suicide. Jane tells Dexter she has decided to sell her house. She explains that she has been slowly leaving her past behind over 35 years—unlike Jessamine who stayed stewing in it or Jasper who fled it all at once—and now she is finally ready to move on. She plans to move to a simple home in London. Dexter enthusiastically suggests they start a private investigation agency together called “Trevally and Son,” moving Jane to tears. Later, while walking their dogs, Jane reveals that Daisy is now living nearby with George and Spencer. She reflects that Daisy, unlike herself at that age, has Stuart’s unwavering support.

A BBC news report announces that the body of Jasper Allen Black has been found in the woods, with his death ruled a likely death by suicide. The discovery follows a confrontation with Daisy Black, who has been revealed to be the daughter of Claire Connolly, the final victim of the “Vale of Health Killers” (361), not Jessamine Black’s daughter as previously believed. Daisy had used the online forum Reddit to track Jasper down. When she confronted him with the truth about her parentage, he tried to strangle her before escaping. The report also reveals that Jasper, who worked as a circus performer named Patch the Clown, had been terrorizing young women at night while in costume. His involvement in the murders at his childhood home is still unknown. His sister, Jessamine, is in a rehabilitation facility awaiting trial for manslaughter in their mother’s death.

On Christmas Eve, seven months after the events at Thornwood, Stuart celebrates the holiday with his brother’s family for the first time in 10 years. He picks up Daisy from the house she shares with her old childhood friend George and George’s dad, Spencer. Daisy, who now looks more mature with a new haircut and clothes, has legally changed her name to Daisy Connolly. As they look at the boarded-up Thornwood, Daisy explains that living so close helps her process the trauma and feel connected to her birth mother. She expresses no sympathy for Jessamine, stating she does not consider her a victim.

Eighteen years earlier, Jasper visits an EMDR therapist, Dr. Twist, to address a severe childhood trauma that has caused him to develop upsetting behaviors. When the therapist instructs him to mentally revisit the event, Jasper recalls the night his abusive father was killed. In his mind, he returns to the secret basement where his father imprisoned young women. He sees his father dead and his sister Jessamine standing over Claire’s body, holding the baby and the paring knife he had smuggled to Claire. Jessamine claims Claire killed their father and had to be stopped from escaping, but Jasper challenges her about why she chose to kill Claire when she could have let her go free. The realization that his sister was as evil as their father convinced Jasper that his entire family was corrupt with an evil “virus” that he also carried. The section concludes with Jasper confirming to Dr. Twist that he is mentally present at the scene of the trauma, ready to begin the therapy.