Matchmaking for Psychopaths

The novel opens on the narrator's wedding day as she reflects on the drama, heartbreak, and death that led her to the altar. She grew up watching romantic comedies with her mother, a woman she describes as beautiful and terrifying in equal measure. Neither parent is in attendance. When she opens an anonymous gift box left outside the bridal suite, she discovers human remains inside. The narrative then jumps back four months.

Lexie, a 30-year-old matchmaker, arrives at a restaurant expecting a surprise birthday dinner from her fiancé, Noah, a medical resident, and her best friend, Molly. Instead, Molly announces that she and Noah are in love. Lexie throws her martini in Molly's face and storms out. At a nearby bar, she meets a handsome stranger named Aidan Lewis, who takes her out for a wild night. They end up alone in a hotel room, where Lexie reveals she had a devastating childhood and Aidan shares his own secret. She blacks out before she can process any of it.

Lexie works at Better Love, a matchmaking company founded by Serena, a glamorous businesswoman who started the service after her own son struggled with dating apps. The company uses an intake questionnaire partly derived from the Hare Psychopathy Checklist, a clinical tool for assessing psychopathic traits, and Lexie specializes in matching clients who score highly on that measure. She conceals the breakup to preserve her professional credibility. At a staff meeting, Serena announces plans to expand nationally and hints she will promote someone to director. Lexie and her rival coworker Nicole both want the position.

Lexie receives a new client, Rebecca Newsom, a luxury car saleswoman with whom she bonds instantly over a shared love of the reality show Love on the Lake. That same day, Aidan reappears at Better Love as a new client. His questionnaire flags him for Lexie's psychopath specialty, confirming he knew what he was before signing up. He suggests they date to make Noah jealous. Lexie refuses but asks him to keep their prior encounter secret.

While researching Rebecca, Lexie traces her to a support group called Children of Murdered Parents (COMP). Lexie attends a meeting and reveals that her own father was murdered in prison. She and Rebecca bond over dinner and shared grief. Lexie lies about still being with Noah, afraid the truth will make her seem unworthy of love, and is so excited by the friendship that she forgets Rebecca's questionnaire flagged her as a psychopath.

Lexie matches Rebecca with Paul, a charming but shallow client. She also orchestrates a night with Noah, cooking his mother's casserole and wearing a backless dress. They have sex, and afterward Lexie secretly photographs him and sends the image to Molly, hoping to provoke a fight. The next day, a gift box appears at Lexie's door containing a human heart on bloodstained tissue paper. Through a recovered memory, the novel reveals what Lexie told Aidan the night they met: Her parents are Peter and Lydia Schwartz, serial killers who murdered women they picked up in bars. As a child, Lexie heard their victims scream and kept the secret for years. Unable to trust the police, she bags the heart and buries it at a wooded trail.

At work, Lexie finds roses on her desk with a card reading "I KNOW WHO YOUR PARENTS ARE." She also learns Noah has not shown up for his hospital shifts and is being reported missing. Paul bursts into the office demanding Rebecca's address and is arrested. Lexie meets Aidan and accuses him of sending the gifts; he denies involvement and appears genuinely shocked about Noah.

Molly confronts Lexie, demanding to know where Noah is. That night, an intruder breaks into the house and arranges body parts on the mantel alongside miniature houses and pink lights. Lexie recognizes Noah's fingers and confirms what she has been resisting: The remains are his. She disposes of them at the wooded trail.

At Better Love, someone splashes red paint around the lobby, scatters plastic mannequin limbs, and writes "MATCHMAKING FOR PSYCHOPATHS" on the wall. Police question Lexie, but she does not mention Aidan because he knows her family secret and could expose her. Nicole privately tells Serena that Lexie's fiancé is missing and suggests Lexie may be dangerous.

After a car crash on icy roads with Rebecca, Lexie finally confesses that Noah left her and she believes he may be dead. Rebecca comforts her, and their friendship deepens. Lexie visits Aidan's penthouse, where a repressed memory surfaces: On the night they met, Aidan told her he killed someone as a teenager and that he recognized her as the daughter of Peter and Lydia Schwartz before approaching her. Lexie accuses him of killing Noah; he denies everything.

On Valentine's Day night, an anonymous text lures Lexie to the Better Love office. Nicole is waiting. She reveals she sent the threatening roses and orchestrated the vandalism with Ethan, her accomplice. Nicole has also discovered through public name-change records that Lexie was born Alexandra Schwartz. She draws a gun and announces her plan to kill Lexie, burn down Better Love, and frame Lexie for the crime.

Aidan, having followed Lexie, hurls Ethan's body through a window. Nicole drops the gun, and Lexie retrieves it and shoots Nicole dead. Aidan finishes off Ethan. They stage the scene as a murder-suicide and flee the burning building. A final repressed memory surfaces: As a 10-year-old, after her parents abandoned her for three weeks, Lexie watched a crime marathon on television that revealed her parents were serial killers. She lured a neighborhood woman into the house, killed her, planted her parents' DNA at the scene, and called the police, engineering their arrest.

Aidan and Lexie become a couple. Using a key Molly once gave her, Lexie plants Noah's remaining body parts in Molly's apartment, then calls in a bomb threat from a burner phone. Police find no explosives but discover the remains, and Molly is arrested.

During a prison visit, Lexie's mother, Lydia, lets slip that she was married before meeting Peter and that her first husband died. Lexie pieces together that Peter killed the first husband as a proof of devotion, that Lydia had a daughter from that marriage, and that the abandoned daughter is Rebecca. Lexie tells her mother she framed her by killing a woman and planting evidence at the scene. Lydia screams for guards, but they are indifferent. Aidan proposes afterward, and Lexie accepts.

On the wedding day, the narrative returns to the prologue. The box contains Noah's preserved head. Rebecca enters and reveals she is Lexie's half-sister, the daughter Lydia abandoned. She found Lexie through a Better Love advertisement, moved to the Twin Cities, and enrolled as a client to engineer their meeting. Rebecca killed Noah, killed Paul, and delivered the body parts as gifts. Her original plan was to kill Lexie out of jealousy, but she grew to like her and redirected her violence toward Noah. However, learning from Lydia that Lexie framed her has turned Rebecca's rage back on Lexie.

Lexie grabs a knife from the snack table and stabs Rebecca to death. Aidan arrives, helps conceal the body, and procures a replacement dress in deep red. The ceremony proceeds on schedule. After the reception, the couple drives Rebecca's body to the lake, weighs it with stones, and watches it sink. Lexie narrates the act as a purification, resolving that her life with Aidan will be perfect "as long as we could keep ourselves from killing too many people" (319).