After they pick up Silas’s car from the airport, he and Marie drive for hours through the mountains and countryside to his home, a massive 19th-century mansion. Marie is stunned by its scale; she knew that Silas must be wealthy, but she didn’t know the extent. She is also unsettled by the small, historic family cemetery in the corner of the backyard. Silas dismisses the local rumors that the house is haunted, admitting that he encourages the myths to protect his privacy. When she points out that keeping the locals away must’ve made it lonely for Christine, he is thoughtful, realizing he has never looked at it that way.

The next day, they visit Christine and Ernest, who live nearby with Christine’s mother Meg. Christine believes that Marie is Maeve and greets her with a warm hug. To explain Marie’s sudden visit and distraught appearance, Silas lies that “Maeve’s” new husband, Aaron, a policeman, was just killed in a car accident days after their wedding. Christine is deeply sympathetic and offers her full support.

Back at the mansion, Silas immerses himself in his writing, leaving Marie alone for days at a time. She realizes that everything comes second to writing for Silas. To combat her idleness, Marie, now going by “Mae,” begins cleaning the dusty house, cooking for Silas, and eventually organizing his chaotic office. Impressed by her efficiency, Silas offers her a job as his assistant. She learns to type, manages his finances, and even gets an Australian driver’s license in Maeve’s name.

Marie becomes close friends with Christine. One afternoon, Christine confides in Marie about her marriage, explaining that she left Silas because, although she still loves him deeply, he is emotionally distant and completely absorbed by his work. She was lonely living with him in the isolated mansion and believes they may have a better relationship living apart. Marie sees that Christine will never move back in with Silas and tells her that she should tell Silas, who is still hoping for reconciliation.

Fiona is now certain that The Midnight Estate is set at Wurimbirra. She also recognizes many of Tad’s traits in Silas and begins to wonder about the rest of the story.

Jack arrives at Wurimbirra with two large traps for the stray cats. He and Fiona go up to Tad’s study to set them. While moving a coffee table, Fiona notices a loose floorboard under the rug. It is clumsily but firmly nailed shut, and Fiona knows that it must be Tad’s work.

After Jack leaves, she pries up the loose board and discovers a hidden metal tin. Inside, she finds a pair of cat-eye glasses, a pearl necklace, a man’s wallet, and two passports. The passports belong to Virginia Joy Winslow, her mother’s name (although it is not her mother’s photo), and a man named Julian Noel Lentfer. She also finds a stack of newspaper clippings about the mysterious disappearances of Julian Lentfer, a deputy police chief, and his wife. She also finds two photos: one of two gravestones, featuring Fiona’s grandmother’s and mother’s names, with a date of death in 1959; and a photograph of a younger Tad, his mother, and a young woman who matches the face in the passport photo.

Shaken, Fiona calls Tad’s literary agent, Rita, and asks about an author named Charity Wilkie. Rita is stunned that Fiona has a copy of The Midnight Estate; she says that it was a secret book written by Tad under that pseudonym. He had been adamant that it never be published in Australia or North America and that Ginny was never to find out about it. Fiona realizes the fictional story she has been reading may be her family’s true history.

Weeks later, Marie’s pregnancy is showing, but she still refuses to go to the doctor. She and Silas fall into a routine, and she gets to know his son Ernest. One night, while Ernest is staying over, Marie is awakened by his terrified screams. She rushes toward his room and recognizes the voice threatening the boy with a knife as Rupert’s. She hides behind a grandfather clock in the hallway, and as Rupert steps past her, she summons all her strength and shoves him. He loses his footing and tumbles down the grand staircase, breaking his neck and dying instantly.

Marie wakes Silas. Upon seeing Rupert’s body and learning he had a knife in Ernest’s room, Silas decides they cannot call the police. He fears the authorities wouldn’t believe their story and would discover the truth about Marie’s identity. They agree to hide the body and realize that the family cemetery is the perfect place. Silas deduces Rupert found them by questioning his neighbor, Mr. Peterson, who remembered the name of his Australian town.

Christine takes Ernest home the next morning, believing he had a nightmare. Silas spends the day digging a grave in the family cemetery. That evening, they bury Rupert’s body inside an existing grave. Silas tells Marie he has buried Rupert’s wallet and his and Maeve’s passports, but he secretly keeps them, along with the news clippings about Rupert’s disappearance, hiding them in a tin box beneath a floorboard in his study.

Months later, Marie goes into labor. To avoid questions at the local hospital, Silas drives her to a larger one in a nearby city. He poses as her husband, “Aaron Winslow,” and signs the birth certificate for their daughter, Cynthia Maeve Winslow. Shortly after, Christine tells Silas she is divorcing him. She loves him, but she cannot remain married to a man who is only a “part-time spouse” due to his immersion in his work.

Over the years, Silas, Marie, Christine, Ernest, and Cynthia become a close, unconventional family, with Cynthia calling Silas her “Uncle Dad.” Marie, terrified that her daughter will be as vulnerable as she once was, pushes Cynthia to excel academically. Fearing this will stifle Cynthia’s creativity, Silas fills her childhood with stories and imaginative play. Marie remains haunted by their secret and vehemently opposes any renovations to the house or yard that might disturb the grave. Finally, one day Silas shows Marie his will, in which he has given the house to Ernest, with the caveat that nothing is to be changed about it until after both he and Marie die.

Eventually, Marie marries a local farmer and moves out with Cynthia. Now older, Silas finally writes their story as a novel and decides to find a small press to publish it, ensuring it will not be sold in Australia or America. He hopes the story might reach a reader and change another life for the better.

After three sleepless nights, Fiona finally catches the two stray cats. She texts Jack, who informs her that their previous owners abandoned them; she decides to keep them and names them Hocus and Pocus.

Fiona drives to her mother Ginny’s farm, bringing the book and the tin she found under the floorboard. Confronted with the evidence, Ginny—whose real name is Jennifer—admits that the story is true. She reveals that she and Tad fought on the day he died because he wanted to tell Fiona and Jon the truth, though she didn’t know he had already written the book. Fiona tells her mother she is a hero, not a victim, and the two share a powerful, long-overdue emotional reconciliation.

Fiona asks if Ginny had a brother, as Marie did in the book; Ginny admits that she does. His name is Rowan, and she hasn’t had any contact with him in the 50 years since she left California. They search online for Rowan and discover that he is alive. Wracked with guilt over his refusal to help his sister and her subsequent disappearance, he became a lawyer and founded “Jennifer’s Voice,” a nonprofit organization dedicated to outlawing coercive control. His biography on the website reveals that Julian’s first wife had also been murdered. 

Overwhelmed with emotion at the knowledge that her brother has spent his life honoring her memory, Jennifer decides she must let him know she is alive. The novel concludes as Fiona picks up her phone and dials his office in San Francisco.