Kirsten King’s debut novel, A Good Person (2026), is a darkly comedic psychological thriller that satirizes contemporary digital culture through the eyes of a deeply unreliable narrator. The story follows Lillian O’Malley, a cynical 29-year-old marketing professional whose life spirals out of control after her casual boyfriend, Henry, is found murdered just days after their volatile breakup. As Lillian navigates the subsequent police investigation and an escalating rivalry with Henry’s long-term girlfriend, she is forced to confront her own increasingly erratic behavior and question her role in his death. King uses this premise to critique the ways in which personal tragedy is commodified for online clout and to explore the fragile nature of identity in a performative world.

The novel examines themes including Perception Versus Reality, as Lillian consistently reinterprets events to cast herself as a misunderstood victim, absolving herself of responsibility for her destructive actions. It also examines Performativity and Identity in the Digital Era, with characters weaponizing social media to control narratives and monetize grief. The potential for genuine connection is explored through the theme of Female Friendship as an Antidote to Isolation, though these bonds are ultimately undermined by jealousy and self-interest. King is also a screenwriter, having written for the television show The Second Best Hospital in the Galaxy and the film Crush. Her background writing for publications such as Teen Vogue and BuzzFeed informs the novel’s satirical voice and its focus on the complexities of modern womanhood.

This guide refers to the 2026 G. P. Putnam’s Sons edition.

Content Warning: The source text and this guide feature depictions of racism, sexual violence, rape, substance use, graphic violence, sexual content, cursing, death, mental illness, bullying, and emotional abuse.

Plot Summary

Lillian O’Malley is a cynical 29-year-old marketing professional in Boston, navigating a job she dislikes at a firm called Fizzle and a casual, four-month relationship with a risk analyst named Henry Davis. On the night of her birthday, Henry comes to her apartment after a bad day at work. Though he is distracted, they have sex, after which Lillian blurts out that it is her birthday. In a gesture of acknowledgment, Henry finds a candle, lights it for her, and Lillian makes a wish to make him love her, no matter what. 

The next time she sees him, several days later, he is drunk and distraught after being passed over for a promotion. When she tries to initiate sex, he becomes aggressive and, despite her attempt to stop him, rapes her. The following morning, Henry unceremoniously breaks up with Lillian, stating he is not in the right headspace for a relationship. Enraged and humiliated, Lillian lashes out, insulting his sexual performance and hairline and falsely threatening to keep a potential baby.

Devastated by the breakup, Lillian spends the next several days in an alcohol-fueled haze, culminating in her urinating on Henry’s doorstep. Consumed by rage, Lillian enlists her best friend, Jamie, to help her perform a revenge hex on Henry that they learn from a YouTube video by an influencer known as the Wellness Witch, who is thinking about hiring Lillian’s firm. After the ritual, Lillian sends Henry a final, ominous text message: “You’re going to get what you deserve” (79). 

The next morning, she learns that Henry has been found stabbed to death outside a bar near his apartment. Panicked but insistent that the hex was a coincidence, Lillian leans into the role of the grieving girlfriend at her workplace, where her colleagues are unaware of the breakup, and is granted bereavement leave. However, while digging into Henry’s online presence, she discovers that he had a girlfriend, Nora, who has pictures of them together on her Instagram profile. 

Lillian’s situation becomes more precarious when she is questioned by the Boston police about her final text to Henry, and she debates the merits of telling them about Nora. She hires a lawyer, Hector Jimenez, and crafts a story that minimizes the text to Henry, painting it as the aftermath of an argument with him when he was drunk.

Lillian discovers where Henry’s wake is going to take place and goes there to assume her rightful place as a grieving girlfriend and to confront Nora. She gets into a screaming match with Nora, and the altercation is broken up by Henry’s mother and sister Amelia, who eject Lillian from the service. The incident is reported to the police, further straining her relationship with her lawyer. 

Lillian’s life continues to unravel as Nora publishes a viral article in Teen Vogue detailing her grief and her discovery of Henry’s infidelity with a woman she calls “Jane.” The article portrays Jane—and by extension, Lillian—as an aggressive homewrecker, which leads to Lillian being ostracized at work. Her increasingly erratic behavior, including sending harassing DMs to the Wellness Witch, results in her being fired from her job.

Surprisingly, Nora reaches out to Lillian, and the two women agree to meet for a drink. They find a strange, temporary bond in their shared experience of being wronged by Henry. Lillian reveals that she felt Henry raped her on their last night together, and Nora confesses that he did something similar to her once in college. They get drunk, and Lillian ends up spending the night platonically in Nora’s bed. The next morning, the police call Nora with news: They are closing Henry’s case, attributing his death to a random act of violence committed by a homeless man who recently assaulted someone else nearby. 

While the official investigation is over, Lillian’s lawyer Hector reveals he suspects her of the murder, having learned from her roommate Elise that Lillian took an Ambien and left the apartment’s front door unlocked on the night of the crime. The final piece of the puzzle falls into place when Jamie confronts Lillian about a charge on her credit card—which was linked to Lillian’s Uber account—for a ride to the crime scene on the night of Henry’s death.

Lillian denies Jamie’s accusation and secretly deletes her Uber account, but the discovery triggers a series of vivid, dreamlike flashes that she recognizes as repressed memories. She recalls taking the Ambien, riding in the Uber to Somerville, confronting a dismissive Henry outside the bar, and fatally stabbing him with a knife she brought in her purse. She confirms the memory is real when she finds the bloody knife hidden behind her bed and her bloody T-shirt submerged in the toilet tank. 

Just as she is grappling with this revelation, Jamie arrives at her door, refusing to let the issue go. When Lillian continues to lie, Jamie sees through her and asks her directly, “Did you do it, Lil? Did you kill him?” (287). Realizing she is caught and seeing the undisguised fear in her friend’s eyes, Lillian blocks the doorway, trapping Jamie inside. As she contemplates the murder weapon in the next room, she asks Jamie if she wants a drink.