In her yellow 1967 diary, Frances records her time in Southampton with Archie. Archie sells records and trinkets at a market and secures concert tickets through a trade. That night they attend the concert together; back at the hotel, Archie tells her she is not merely a passing adventure. The next morning, he gives her a gold bracelet she had seen amidst his trinkets at the market.

He then produces a ruby ring he had been concealing. He calls it a family heirloom, confesses his love, and proposes. Frances accepts, and they marry the same day at a registry office with strangers as witnesses. Frances closes the entry by writing her new name—Frances Foyle—repeatedly across the final page.

In the present, Annie and Jenny rule out searching for Birdy until conditions improve. They turn to examining the antique knife found in Peony’s back, retrieving the estate’s insurance inventory. They find that the dagger is catalogued with a ruby ring, alongside legal documents and a typed note from 1970 explaining a dispute originating in 1900: Alexander Gravesdown owned the dagger and accused his valet, Owen Foyle, of prying a ruby from it to make a ring for his wife. Owen claimed the ring was a family heirloom but surrendered it to keep his family housed and employed. Annie realizes that if the loose ruby found at the crash scene came from the dagger’s handle, the weapon was in the car that night—and the fourth, surviving passenger most likely had it.

Nervous about being alone in the big house, they haul mattresses into the library and lock themselves in, noting that Beth’s and the cleaners’ key sets are still unaccounted for. Jenny reveals that when Annie showed her the papers she took from Peony’s house, she was troubled by the fact that one of the fortunes bore Annie’s name.

The floorboards creak, and they hear a muffled cough. Armed with a fire poker and a brush, they station themselves beside the door, expecting Beth. Archie sneaks in instead, holding a set of keys and Peony Lane’s file. When they confront him, he is surprised that they are there. When Annie mentions Samantha’s body found in the Bentley’s trunk, Archie says he put it there.

In her 1967 diary, Frances writes that as they drive back from Southampton, Archie suggests they stay in Castle Knoll and open a bakery. Frances wants a genuinely new life, not just a different version of her old one. She proposes London instead. When she asks whether his plan to expose the Gravesdowns still stands, he says he will soon have money to buy back the Foyle farmhouse and start a family—an assumed future that unsettles Frances.

Archie then confesses the full history of his feelings: He has loved her for years, dated her friend Rose only to get closer to her, knew her ex-boyfriend was unfaithful before she did, and used their shared investigation as a pretext to win her over. Angry, Frances demands he take her to Peony Lane’s house in Crownell. A blond woman—not Peony—answers the door. Archie identifies her as Birdy Sparrow, older sister of the missing Emily. When Birdy spots the engagement ring on Frances’s finger, her shock turns to fury, and she demands to know what Archie has done.

In the present, Annie confronts Archie about the murders, the break-in, and the marriage certificate she and Crane found at Peony’s house. Only the certificate genuinely surprises him. He claims he came to the Hall to return Peony’s file, but he denies being the person Beth admitted to the house, insisting he was at the farm all morning.

Then, he tosses her the keys he was carrying—unfamiliar, bearing a vintage American souvenir key ring—explaining they were in Samantha’s handbag with the file. He recovered the wrecked Bentley after it was found inside the collapsed pub, intending to resume the investigation he and Frances never completed.

Samantha had come to the farm, offering the file in exchange for Frances’s yellow diary. He went into the house to get the diary as a bargaining tool, and when he returned outside, he found her on the ground, dead. He hid her body in the Bentley’s trunk to shield Eric and Beth. He adds that the night before her death, Peony told people at the Dead Witch that an old fortune was reaching its conclusion. He hands Annie the worn yellow diary and says the secrets need to be set free, then walks out.

In 1967, Birdy identifies Frances’s ring as Olivia Gravesdown’s wedding ring. Frances removes it in horror and accuses Archie of knowing; his expression confirms it. Birdy ushers them inside, and Peony emerges from another room—dressed plainly, nothing like her fortune-telling persona.

Peony hands Archie a written fortune in an envelope; he reads it and dismisses it, devastating Frances, who has confided her fears about her fortune to him and now realizes that he was being condescending. She breaks down and accuses him of stealing. Archie pivots to ask Peony where she has hidden a knife. The mention of the knife causes Frances to connect the ruby on Olivia’s ring to the ruby-handled dagger. She senses that Archie’s involvement in the Gravesdown tragedy runs far deeper than he has admitted. She demands that all three of them tell her everything.

Annie and Jenny stay up through the night reading the yellow diary, but they find it does not reveal what happened the night of the crash. Examining Peony’s file, they discover it contains not a record of Peony’s life but the original evidence dossier against Edmund Gravesdown—material that should have stayed with the police.

The next day, Annie focuses on timing: Why is this all happening now? She connects the pub collapse and the Bentley’s reappearance as the probable trigger for recent events, and she proposes that its discovery made Peony discover that the fortune she thought was for Archie was for herself.

Reading a victim’s statement in the file, Annie notes that an unnamed Gravesdown family member—not Edmund—later threatened the woman into silence. She advances a new theory: Olivia was complicit in covering up her husband’s crimes. Frances would only have protected a murderer if the victim deserved it or if the killer was someone she loved. Annie concludes both conditions likely applied, and that the killer was either Archie or Ford.

A 1970 addendum to Frances’s diary opens the chapter: She reflects that she spent years trying to inhabit a “shadow” that was never hers.

In 1967, Peony states bluntly that all three Gravesdowns deserved their fates. Archie recounts the night of the crash for Frances. Eric had worked as Edmund’s valet and was gradually coerced into delivering bribes and intimidating witnesses. Samantha, who works at the police station, secretly collaborated with Eric to preserve evidence, and Peony joined their effort. One evening, Archie visited Gravesdown Hall and found only Olivia home. Too late, he understood that she intended to use him as leverage against Eric, who had begun resisting the family. As Edmund, Harry, and Olivia prepared to drive him to the Foyle farmhouse, Archie pocketed the ruby-handled dagger from the library desk for self-defense.

At the farmhouse, Olivia dragged him to the river, held his face underwater, then seized the dagger from his pocket and pressed it to his throat. Archie broke free and struck her in the head with a rock; she collapsed. Edmund appeared and ordered Archie to help load Olivia into the trunk and Birdy into the back seat. Birdy told Archie to run, and he fled. Birdy then discloses what she has never told anyone: Within moments of the car pulling away, Olivia was alive and screaming from inside the trunk.

In the present, alone in the library, Annie re-examines the security footage from the morning of Peony’s murder. She realizes that the figure at the door, who they all assumed was Beth, is not definitively Beth—an umbrella hides the face. Zooming in on the visitor’s hand, she recognizes her mother’s key ring and hand. Her mother, recently grown close to Birdy, is also the only other person who knew about the ceramic cat.

Annie calls her mother repeatedly with no answer, texts Jenny, and speeds away. She briefly stops at the Gravesdown crash site and notes how close the village is—someone could have reached the scene and slipped back before being seen. She calls Crane to ask about Saxon’s alibi; he confirms it is airtight, as is Elva’s.

Annie arrives at Saxon’s house and offers him the yellow diary, presenting it as his right to choose whether to learn the truth about his family. Saxon says rumors have circulated for years, and he harbors no illusions. He adds that he does not think it a coincidence that someone died just as he located a key piece of evidence in his own investigation. When Annie asks what it is, he invites her in for a drink.