The New Couple in 5B is the 21st novel by American author Lisa Unger, who also writes under the name Lisa Miscione and is best known for her contemporary thriller novels. The novel follows a young couple, Rosie and Chad Lowan, who inherit an expensive apartment in an iconic building with a dark history. As the Lowans try to build a life together, Rosie begins to suspect that the building and its residents are not what they seem. Major themes in the novel include belief in magic and the supernatural, the interaction of memory and place, and the dangers of true crime culture.

This study guide uses the 2024 Park Row Books e-book edition of the novel.

Content Warning: The source text and this guide contain discussion of death by suicide, domestic violence, sexual assault, and child loss.

Plot Summary

In the prologue, an unnamed narrator stands on the ledge of a building and—using a second-person narrative perspective, speaks directly to an unidentified second character, who begs them to climb down. As the novel begins, true crime writer Rosie discusses her new project—a book about the mysterious Windermere Apartments—with her editor, Max. Rosie and her husband, Chad, learn that Chad’s uncle Ivan, whom the couple cared for in his final illness, has left them his apartment in the Windermere, infuriating his daughter, Dana. The next day, while on a tour of the Windermere, Rosie thinks she sees the corpse of a young boy in the basement. The doorman Abi assures her there are no children in the building.

The narrative shifts briefly to 1963, when a writer named Paul Winter and his unfaithful wife, an aspiring dancer named Willa, live in the apartment. In the present, Rosie has a panic attack on the opening night of Chad’s new play, a musical retelling of Shakespeare’s Macbeth. Shortly after, Rosie and Chad move into apartment 5B of the Windermere. Despite the building’s history, Rosie is hopeful—until she learns that the building is wired for a high-tech automated intercom system that seems to always be listening. In 1963, Willa Winter decides to end her mysterious affair and devote herself fully to Paul.

Rosie agrees to meet Dana, who claims to have information about Chad. On the way, a box of documents Ivan left for Dana disappears. Max suggests she may have imagined bringing the box, pointing to her history of visions. In 1963, Willa tells Paul she’s pregnant. Privately, she hopes the baby is his and not her ex-lover’s. In the present, Max accompanies Rosie to Dana’s studio, where they find several pictures of Chad and Dana, who has died by apparent suicide. Chad warns Rosie not to speak to investigators without him and a lawyer, explaining that Dana had been obsessed with him for years. At the Windermere, Abi insists Rosie left without the box of documents. She finds it in her apartment, but a letter from Ivan to Dana is missing.

A meeting with her psychologist reassures Rosie that her visions are a trauma response and not real. Max loses his job. In 1963, Willa is confronted about the affair by Charles and Ella’s young son, Miles. In the present, Rosie presses Ella for information about Abi and the building, but Ella remains vague. Rosie has a vision of the young boy from the basement falling down an elevator shaft. Soon after, she learns she is pregnant. Detective Crowe reveals that Dana’s death has been ruled a homicide, and that she planned to sue Chad and Rosie for the apartment. In 1963, a pregnant Willa resumes her affair, confident the baby is her lover’s. In the present, Rosie learns that Ella and Charles’s son died in the Windermere. She arranges a meeting with a resident named Xavier, who seems unwilling to talk in the building. Later that night, Xavier is found dead in front of the Windermere, having apparently jumped from the roof.

Just days after finding out she is pregnant, Rosie loses her baby. Rosie is questioned about Xavier’s death. In 1963, Miles catches Willa with her love only hours before falling to his death in the elevator shaft. Flashbacks reveal that Chad was charged with murdering his high school girlfriend Bethany, though he was later exonerated. His parents died just a year later. In the present, Rosie discovers a photo of Xavier and Dana with Chad and Lillian, Ella and Charles’s daughter, in the background. In 1963, at the funeral of her son Miles, Ella tells Paul about Willa’s affair.

Rosie interviews Arthur Alpern, a historian of New York architecture who claims that buildings hold the memories of their residents. At Xavier’s funeral, the ghost of Willa Winter warns Rosie that she is being watched. Rosie’s sister Sarah appears, explaining that she dreamed Rosie was in trouble. They leave the funeral early and sneak into the Windermere’s security room while everyone is at Xavier’s funeral. In 1963, Willa has one final encounter with her lover, who is revealed to be Abi. Paul catches them and kills her, then himself. Rosie finds nothing in the security room and admits to Abi that she is looking for evidence against him.

Betty Cartwright, a nurse who worked with Ivan and believed he wanted the apartment to go to Dana, is found dead, and Detective Crowe identifies Chad as a suspect. When she can’t contact Chad or their lawyer, Olivia, Rosie leaves 5B. At Olivia’s house, Rosie discovers evidence that Olivia and Max are having an affair. When he discovers that Rosie is gone, Detective Crowe orders her to come to the station the next morning or face arrest. When Rosie confides in Charles and Ella, the couple feed her soup laced with fentanyl and restrain her with Abi’s help. Ella reveals that she and Charles have kidnapped Chad and Olivia in hopes of securing the apartment. Rosie escapes, and Abi chases her to the roof. Charles threatens to kill Sarah, who has also been kidnapped. Rosie agrees to sign, but she and Sarah overpower Charles, Ella, and Abi and escape their bindings. Charles is hospitalized, and Ella and Abi are arrested for attempted murder.

Six months later, just as Rosie and Chad are settling back into their life, the brother of Chad’s late ex-girlfriend dies in prison of a fentanyl overdose. Chad admits to killing him and Bethany, as well as Dana and Betty Cartwright, before jumping off the roof of the Windermere. In the epilogue, Rosie sells the Windermere apartment. Her book becomes a New York Times best seller.