Lost Lambs is Madeline Cash’s debut novel. Since its January 2026 release, it has become a national bestseller and New York Times Editors’ Choice award winner. It blends elements of family drama, cultural satire, and crime caper in its examination of the dysfunctional Flynn family as the parents navigate a newly “opened” marriage, the daughters attempt to establish and refine their own identities, and they all become involved in a high-level conspiracy involving human trafficking and covert community surveillance. Key themes include Latent Misogyny and the Sexualization of Minors, Open Marriage as Liberation and Engine of Domestic Collapse, and Adolescent Agency Under Institutional and Parental Failure.

This guide refers to the 2026 Farrar, Straus and Giroux hardcover edition.

Content Warning: The source material and guide feature depictions of substance use, suicidal ideation, cursing, physical abuse, child abuse, disordered eating, antigay bias, sexual harassment, child sexual abuse, gender discrimination, sexual content, illness, rape, animal death, and death.

Plot Summary

Harper, the youngest member of the Flynn family, comes to speak with a priest named Father Andrew. Harper’s father, Bud, visited the priest last week to discuss a “friend” experiencing suicidal ideation, and now Harper reports that this friend is actually her father. Harper herself is a prodigy who has stopped attending classes because she finds them dull. 

Bud lives in a minivan inside the garage of his family home. Catherine, his wife, wanted an open marriage, but Bud didn’t. He thinks that Catherine is sleeping with their neighbor, Jim Doherty. When Jim showed Catherine his ceramics and called her an artist, Catherine began opening up to him. Catherine considered an affair first, ultimately convincing herself that exploiting a “moral loophole” would be better.

Now, Catherine forbids her eldest daughter, Abigail, from meeting her 22-year-old boyfriend, Wes, but Abigail goes anyway. About a month ago, Abigail met Wes when she and her best friend, Tibet, convinced Tibet’s cousin, a security guard, to sneak them into a party at the home of Paul Alabaster, a shipping magnate and Bud Flynn’s boss. When a smarmy man called “Dolt” offered her champagne, Wes said not to drink it. Abigail’s classmates think that she’s dating a “warlord,” but Wes is sensitive.

Meanwhile, Louise—the middle daughter—decides to enter her school’s Inner Beauty Pageant, and she logs into the family laptop to message yourstruly, her internet boyfriend. He wants her to learn Arabic and promises her a “victory.” In the first round, she passes out after holding her breath for over three minutes—her “talent”—and she is prohibited from continuing. Yourstruly promises that they will “avenge” her, and he asks if she can procure some chemicals used to make fireworks.

One day, Bud’s supervisor, Allen, gives Bud some brochures on local assistance programs and tells Bud that he must pick one. He selects Lost Lambs Christian Guidance. It meets twice a week, led by a woman named Miss Winkle. At his first meeting, Bud admits to having marital problems. That night, Catherine says that she hasn’t slept with Jim “yet.” Bud gets drunk and calls Miss Winkle. She makes him tea, and they kiss.

Meanwhile, Harper gets in trouble for posting a conspiracy theory regarding spying equipment hidden in the town square on a school bulletin board; when she accuses the Mother Superior of censoring her, she is suspended again, and Bud decides to send her to a camp for troubled children.

About a month into Wes and Abigail’s relationship, he stops picking her up at school. When Wes sees that Alabaster’s next guest list includes Abigail, he hires a private investigator. He tells Abigail that he has to protect her and that that’s why he’s keeping his distance. Abigail shows Tibet her invitation, and Tibet recognizes Alabaster Manor’s address. Abigail is delighted, thinking that she’ll see Wes there.

By the time Harper returns from camp, Bud feels that his life is improving. He wants to take Miss Winkle on a trip, so he decides to try to earn a work bonus. In doing so, he finds discrepancies in spreadsheets that Harper previously discovered; he dismissed her concerns at the time, but now he starts asking questions. However, his supervisor tells him to let it go. Bud is then summoned to Alabaster Manor for a meeting with Paul Alabaster. Bud explains the pattern of inconsistencies he found, and Alabaster tells Bud that he values loyalty, implicitly threatening Bud’s daughters. He cuts Bud a big check.

Meanwhile, Catherine plans a night at a hotel with Jim, but then he shows her his “art”: 50 misshapen ceramic vaginas. Catherine is revolted, and Jim calls her prudish. After overhearing gossip about Bud’s relationship with Miss Winkle, Catherine confronts her husband, and he reminds her that she’s sleeping with Jim. She denies it; they fight and then end up in bed. Afterward, Catherine says that she’s ready for a divorce.

Wes’s private investigator shows him a photo of three men wearing Venetian masks, standing around an unconscious girl. Wes recognizes Alabaster and “Dolt.” The investigator says that “Dolt” is Alabaster’s doctor and that the third man is Alabaster’s religious consultant, Father Andrew. When Wes gets back to Alabaster Manor, he learns that he’s been fired.

After his windfall, Bud decides to take his daughters to see his father. However, at the airport, they learn that Louise is on the no-fly list. At home, Bud finds a dangerous collection of substances and a pyrotechnics manual in the treehouse. Louise says that yourstruly, her boyfriend, was teaching her to make a bomb to blow up the beauty pageant. After this, Bud and Catherine declare a truce. Catherine calls a local contractor called “Remy” about a leak in the bathroom. When Remy, whom Catherine is surprised to learn is a beautiful woman, finds a baggie of pills behind the bathroom mirror, Catherine claims that she has no idea what they do; Remy suggests they find out. High, Catherine and Remy kiss.

Tibet researches the origin of Abigail’s invitation and eventually persuades the calligrapher to give her an invitation list. She solicits information about Alabaster from various conspiracy forums. Meanwhile, Wes’s investigator takes him to a cargo container in the harbor. It’s empty now, but people were clearly living inside. On the night of the party, Tibet calls Harper and Louise about Abigail and her suspicion that Alabaster is running a child-trafficking ring. Both the Flynn parents are out on dates, but Harper calls a cab. Harper and Louise get Wes, who brings his roommate and a massive rifle, and they go to the manor.

By this point, an attendant has led Abigail to Alabaster’s study, where she learns that Wes was fired. Alabaster pours her a drink and describes his research on parabiosis: the sharing of blood between two organisms, a process he believes will extend youth. When his circle began clamoring for a trial, he began holding these parties. Abigail cannot feel her hands, and Alabaster informs her that the drink contained a paralytic that will wear off in 30 minutes. Dolt takes some of her blood, and the men drink it. Afterward, Dolt locks her inside another room off the study, which is where Wes, Harper, and Louise find her, along with 20 other girls, all from Albania.

Wes, Harper, and Louise bring Abigail and the others home. Bud demands answers, and Harper explains. Catherine comes home and calls the police while Bud goes to Alabaster Manor; everyone is gone. When he enters, a telephone rings, and he answers. It’s Alabaster. Bud tells him that he will get caught, but Alabaster disagrees.

Most of the kidnapped girls are sent home, but some stay. The Flynns are heroes. When Bud takes Miss Winkle on an overnight trip, Catherine and Remy watch Perry, Miss Winkle’s daughter. While Louise attends her mandated community service at the Jewish retirement center, she meets Caleb, who says that he admires her for protesting the pageant. Louise stops eating bacon and begins observing the Sabbath.

The Flynns and their various romantic partners go out to a restaurant to celebrate Harper’s birthday. While there, they attract the attention of Jim’s son, Myles. Myles believes that girls are inferior, an idea he learned from his father. Now, he regards the odd mix of people. Despite the variety of identities, they say grace together. Myles is struck by how warm and loving the gathering is and feels bewildered. When they notice him staring, they wave him over, and he finds himself happy as he listens to their easy banter. When Jim calls him back to the table, Myles hesitates, not wanting to leave the group.