Sally Hepworth’s 2026 novel, Mad Mabel, is a domestic-suspense thriller that centers on Elsie Mabel Fitzpatrick, an 81-year-old woman living a quiet, anonymous life in Melbourne, Australia. Her world is upended when the death of a neighbor resurrects her notorious past as “Mad Mabel,” the youngest person in Australian history to be convicted of murder. As a media circus descends on her small street, Elsie recounts the story of her traumatic childhood for a pair of young documentarians, confronting the events that led to her conviction 66 years earlier. Alternating between past and present, the novel explores themes of The Harms of Misinformed Public Opinion, Female Friendship as a Lifeline in a Hostile World, and Fear of Emotional Vulnerability After Childhood Trauma.

A New York Times best-selling author, Hepworth is known for writing domestic thrillers such as The Mother-in-Law and The Good Sister, which often examine complex family dynamics with a darkly humorous tone. Mad Mabel subverts the genre’s conventions by featuring an octogenarian protagonist, using her marginalized status to create psychological suspense.

This guide refers to the 2026 St. Martin’s Press First US Edition.

Content Warning: The source material and guide feature depictions of illness, death, child death, death by suicide, graphic violence, sexual harassment, child sexual abuse, child abuse, physical abuse, emotional abuse, bullying, antigay bias, gender discrimination, mental illness, substance use, and cursing.

Language Note: The source material uses the word “mad” to refer to mental illness, particularly in the sections of the story that take place in the 1940s and 1950s. This language was common at the time and reflects the characters’ limited understanding of mental illness and the harmful effects of stigma. In this guide, the usage of “mad” to refer to mental-health conditions is limited to direct quotations and discussions of a nickname that the protagonist is labeled with in childhood.

Plot Summary

The novel alternates between two timelines in the life of Elsie Mabel Fitzpatrick, an 81-year-old woman living on Kenny Lane, a small cobblestoned street in Melbourne, Australia. Elsie is six feet tall, sharp-tongued, and fiercely independent. She was born Mabel Elsie Waller in 1944 but adopted her middle name and her mother’s maiden name decades ago to conceal a notorious past: At 15, she became the youngest person in Australian history convicted of murder.

In the present, Elsie’s quiet life is disrupted when a photocopied news article about her past is slipped under her door. She shows it to her best friend, Daphne Barton, who visits daily for tea. Elsie suspects her neighbor Joan Waters of leaving the news clipping. Shortly after, Persephone, the seven-year-old daughter of Roxanne, a single mother across the lane, mentions that the elderly neighbor Ishaan hasn’t answered his door and that his vitamin packages are piling up. Elsie climbs the fence to check on him and finds Ishaan dead on his kitchen floor. Joan publicly accuses Elsie of foul play and asks the gathered neighbors if they know who Elsie really is. Peter Pantages, a kind neighbor whom Elsie is secretly fond of, tells Joan to stop.

The narrative shifts to Elsie’s childhood (when she went by “Mabel”). Born into wealth, she grew up at Rosehill, a grand Edwardian estate. Her father, Elliott Waller, was obsessed with the house; her mother, Mary Fitzpatrick, drank heavily and was emotionally volatile. Mabel was friendless and relentlessly bullied for her height, red hair, and intelligence. At age six, she learned that other children called her “Mad Mabel,” though she didn’t know why.

When her parents traveled abroad, Mabel was cared for by her aunt Cecily (Cess), her mother’s younger sister, and Cess’s close companion Vanessa (Ness), a librarian. Ness encouraged Mabel to keep a diary and gave her Anne of Green Gables, comparing Mabel to its red-haired protagonist. Ness was the first person whom Mabel recalled hugging her simply because she wanted to. Mabel yearned for a “bosom friend” like the one Anne finds in the novel.

At 14, Mabel sustained severe injuries in a fall at summer camp. While she was hospitalized, her mother revealed that Mabel’s younger sister, Katharine (Kitty), had died of polio at one year old after being found playing with the quarantined Mabel on the porch. Elliott blamed Mabel, believing that she had unlocked the door and let Kitty onto the porch out of jealousy. Elliott told the neighborhood that Mabel killed her sister. Mabel realized that this was the source of her father’s lifelong contempt and the community’s hostility toward her.

During the same hospital stay, Mabel told her mother that she had witnessed Elliott having sex with a woman named Susan McGinty at a party. Mary slapped her, strode to the hospital balcony, and threw herself over the railing. She died from the fall. Elliott visited two days later, accused Mabel of causing Mary’s death, and left for London, placing Mabel in Cess’s care.

In her grief, Mabel threw her copy of Anne of Green Gables against the wall. A girl—Daphne—appeared in the doorway, exuberant and insistent that they become friends. Mabel accepted, feeling like she had found her bosom friend at last. Cess and Ness took over Mabel’s care at Rosehill. Cess told Mabel that no three-year-old should carry blame for Kitty’s death and that Elliott resented Mabel because she had outshone him from birth.

At school, Mabel developed a secret relationship with Mr. Loukas, a young history teacher who told her he loved her. When Mabel eventually went to his house, his fiancée, Tessa, answered the door and revealed that Mabel wasn’t his first affair with a student. Mabel punctured his car tire and left. The next day, Mr. Loukas was found dead, crushed under his car while changing the flat. Tessa eventually confessed to killing him, but rumors of Mabel’s involvement persisted, fueled by Elliott. Meanwhile, Mabel found genuine connection with Christos, a Greek classmate who treated her with respect and became her first real love.

Elliott returned to claim Rosehill, but Cess revealed that Mary’s parents’ will named Mabel as the heir, with Cess as the trustee. Elliott threatened that the house would become his if no other living relatives remained, implying that he might kill Mabel. Months later, Mabel came home early from school and discovered Cess and Ness in bed together, their romantic relationship revealed for the first time. Elliott was raging at them, calling their relationship “unnatural.” Mabel, overwhelmed, fled to Daphne. When she returned about an hour later, she found Cess dead on the floor and Elliott standing over the body. He told Mabel that he intended to frame her for the crime. Mabel seized her father’s sterling-silver-handled umbrella and beat him to death. She covered Cess’s body with a silk bathrobe, smoothed her hair, and then went to say goodbye to Daphne.

In the present, the media discovers Elsie’s identity. Two YouTubers, Adeem Anand and Libby Conquest, who host a true-crime channel called “AdLib,” persuade Elsie to tell her story on camera. Meanwhile, a man named Shane, Persephone’s father, begins appearing on the street. Roxanne reveals that she has a restraining order against him, but it has proven ineffective; the family has moved six times to escape him. Elsie offers to babysit Persephone on Roxanne’s work nights.

Young vigilantes attack Elsie, spraying her with a blood-filled water pistol. She breaks her wrist shielding Persephone. Roxanne, after learning Elsie’s identity, asks that Persephone stop visiting, but the girl defies her mother and continues coming. Joan, remorseful for reporting Elsie to the police, sends her nephew Bailey Andrews, a lawyer, to intervene on Elsie’s behalf when the police take Elsie in for questioning regarding her neighbor’s death.

During Elsie’s interviews with Adeem and Libby, she admits that, during her trial for her father’s murder, a court expert diagnosed her with multiple personality disorder because Daphne isn’t a real person but a figment of Elsie’s imagination. Elsie refuses to call Daphne “not real,” insisting that when an imaginary friend is your only friend, the distinction is meaningless. She also reveals that she gave birth to a son while incarcerated, a boy adopted by Ness. That boy is Peter, her neighbor on Kenny Lane, who has always known that Elsie is his mother.

The YouTube documentary, titled Magnificent Mabel, goes viral. Public opinion shifts dramatically: Flowers arrive at Elsie’s door, and a skywritten banner reads, “FORGIVE US, MABEL” (330). When Shane returns a final time, smashing through Persephone’s bedroom window and seizing her at gunpoint, Elsie charges across the lane. Persephone bites Shane’s arm, and when he aims the gun at the child’s head, Elsie lunges in front of her. The gun fires, and everything goes black. As Elsie loses consciousness, she feels lucky to hear the voices of the people who love her calling her name.

A closing newspaper article reveals that Rosehill has passed to Peter as Elsie’s biological heir and that the toxicology report has cleared Elsie of involvement in Ishaan’s death, which resulted from a lethal vitamin overdose. In the final chapter, narrated by a grieving Persephone, the child is comforted by a new friend she calls Daisy, who wears magenta glasses and a bedazzled Eiffel Tower T-shirt, details identical to Daphne’s appearance throughout the novel. Daisy tells Persephone that she also knew Elsie: “Except when I knew her…she used to call me Daphne” (344).