My Husband’s Wife is Alice Feeney’s eighth novel. Inspired by her love of Agatha Christie, Feeney aims to include a twist in each of her novels that makes readers gasp. Feeney says all her story ideas come from threads in her real life. She got the idea for My Husband’s Wife while her remote 16th-century home in Devon was being renovated. She returned home for a run and found that and her key didn’t fit the door. When she rang the bell, a stranger answered the door. Though the stranger turned out to be an apprentice to one of the workmen, the unsettling moment prompted her to question: What if the person in your home isn’t who they claim to be?

Feeney is a New York Times and international bestselling author whose novels have been translated into more than 25 languages. Before becoming a full-time writer, she spent 15 years working as a journalist and producer for the BBC, including on programs like Woman’s Hour, Newsnight, and the News at Ten. Her previous novels include Sometimes I Lie (2017), I Know Who You Are (2019), His & Hers (2020), Rock Paper Scissors (2021), Daisy Darker (2022), Good Bad Girl (2023), and Beautiful Ugly (2025). Her work has been optioned for both film and television.

The source material comes from the 2025 Flatiron Books eBook edition.

Content Warning: The source material and guide feature depictions of mental illness, death by suicide, suicidal ideation, sexual content, child abuse, emotional abuse, illness, and death.

Plot Summary

Eden Fox goes out for an early run on the cliffs near her new home in Hope Falls, Cornwall. She and her husband, Harrison, have recently moved there for a fresh start, as their daughter, Gabriella, now lives in a residential care facility. Eden is preparing for her first art exhibition and is trying to reclaim a sense of self after years devoted to motherhood. When she returns home from her run, her key no longer works. A woman who looks almost exactly like her answers the door, wearing Eden’s dress and wedding ring, and calmly claims to be Mrs. Eden Fox. Harrison supports the stranger and insists that he has never seen Eden before.

With no phone or identification, Eden is treated as an intruder and forced to flee. Desperate to prove her identity, Eden tries the police, her art gallery, and finally The Manor, the facility where Gabriella has lived since a traumatic accident years earlier left her with intellectually disabled and nonverbal. At The Manor, Gabriella whispers that the woman in front of her is not her mother. Soon after, Eden receives a mysterious message directing her to a cliffside spot she once shared with Harrison. At sunrise, someone approaches from behind, and Eden falls to her death.

The narrative shifts back in time by six months. Olivia “Birdy” Bird, a seasoned London detective, learns that she has terminal cancer. Shortly thereafter, she inherits a house in Hope Falls, called Spyglass, from a grandmother she barely remembers. Among her grandmother’s belongings, Birdy finds a letter from Thanatos, a company that claims to predict a person’s death date. Intrigued, she undergoes their process and receives her own “deathday.” With limited time left, Birdy relocates to Hope Falls, intending to settle unfinished business.

When Eden disappears and a body is found below the cliffs, Birdy arrives at the local station and reveals that she is the new senior detective assigned to the case. She is partnered with Sergeant Luke Carter, a local officer with whom she had a one-night stand when she first came to see Spyglass after inheriting it. As they investigate, inconsistencies surface. Harrison’s statements don’t quite align. Eden’s phone is found hidden at home. The body recovered from the beach is too badly damaged to identify. Birdy learns that Harrison is the CEO of Thanatos. Despite the company’s extraordinary claims, it is largely built on accessing medical data and projecting mortality dates—educated guesses that the company presents as incontrovertible prophecy. Harrison secretly monitored Birdy during her visit and erased her file. Meanwhile, Carter discovers that Gabriella’s caregiver, Mary, is the same woman who appeared at Eden’s house claiming to be her. Mary has been impersonating Eden.

As suspicion tightens around Harrison and Mary, the investigation grows more personal. Carter is married, though unhappily, and his wife, Jane, begins to sense his divided loyalties. Birdy’s health worsens as the date predicted by Thanatos approaches. During a tense confrontation at Spyglass House on the night of the town’s Day of the Dead celebration, Birdy reveals that she is Harrison’s first wife and Gabriella’s biological mother. Years earlier, when Gabriella was injured in what was believed to be a bicycle accident, Birdy blamed herself and left the marriage. Eden, who was Gabriella’s nanny at the time, married Harrison afterward. Six months before the present investigation, Birdy visited Gabriella and learned the truth. On the day of the “accident,” Gabriella had seen Harrison and Eden together. Later, Eden pushed Gabriella down the stairs and staged the incident. A phone call to Birdy was meant to distract her and shift the blame. After discovering this, Harrison, Birdy, and Mary conspired to confront Eden at the cliffs. The plan was to confuse her, driving her to despair by making her believe that she was no longer who she thought she was, then push her from the cliff and make her death look like a suicide. Mary was the woman posing as Eden in the opening chapters. However, Birdy insists she did not push Eden herself.

In the present, Carter discovers a hidden tunnel beneath Spyglass House that leads to the beach. He is knocked unconscious and later wakes in the passageway with Birdy. She admits she struck him to protect him from what is coming and urges him to escape through the tunnel. She also tells him Harrison intends to flee the country with Mary and Gabriella and has offered financial security to Carter’s struggling family in exchange for silence. Believing her deathday has arrived, Birdy takes an overdose of pills. Carter finds her unconscious and performs CPR while the town celebrates around a bonfire. She survives.

One year later, Birdy’s cancer is in remission. She lives at Spyglass with her dog, Sunday, and shares a renewed bond with Gabriella, who visits often. Harrison has relocated to Switzerland with Mary. Carter receives a promotion, and his parents return to Hope Falls. In a final revelation, Carter’s wife, Jane, confesses that she was the one who pushed Eden off the cliff. Jealous of Carter’s feelings for Eden and aware of the conspiracy, she acted alone. Disguised in a skeleton bride costume during the Day of the Dead festivities, she had also intended to kill Birdy but believed she had already died. Jane admits she knows about Carter’s affair and warns that she “still might” act again.