Valley of the Moms

The novel opens with a prologue set in winter: A couple walking near the canoe launch along the Ipswich River in Essex County, Massachusetts, discovers a woman's frozen body on the riverbank. The narrative then alternates between two timelines, one following Anna Plummer in the months before her death and the other following her husband, Denny, in the months after.

Anna is a forty-two-year-old mother of two who lives in Hamilton, a wealthy New England town, with Denny, their seven-year-old daughter Louisa, five-year-old son Ben, and dog Hank. A former aspiring artist turned copywriter, Anna is restless and dissatisfied. She moved from the Hamptons hoping for a simpler life, but Hamilton's rigid social hierarchy makes her feel out of place. Her closest confidante is Diane Maguire, known as Di, her best friend of 30 years, who lives on a sprawling Hamilton estate. The two met as children at a barbecue in Newburyport, but even early in their friendship, Di displayed flashes of resentment, once telling Anna she was "ordinary."

The narrative jumps forward. Police arrive at Denny's home. Anna has been missing for days. Two officers, including Officer Malkin, known locally as "Sticks" for his high school hockey career, deliver the news: Anna's body has been found near the Ipswich River canoe haul-out. She died of exposure. Denny collapses. His children are downstairs with Anna's mother, Corina Denton, unaware.

Returning to Anna's timeline, the story traces the conflict that ignites everything. Anna discovers that the Hamilton Parent-Teacher Organization (PTO) charges a "premium membership" for early access to school events. When she tries to register for a class dance, tickets sell out instantly because premium members received priority. Anna objects publicly that the system is classist and meets with PTO president Mimi Mar, a petite, fashion-conscious blonde who has held the position for six years. At Honeycomb, a popular local bakery, Mimi dismisses Anna's concerns and warns her to watch what she says.

Denny met Anna at a Montauk bar when she was 32. During the pandemic, Anna pushed him to turn his woodworking hobby into a business, and he left his IT career. She was binary in her worldview: You succeed or you fail.

Back in Denny's post-death timeline, Sticks reveals that Anna's death was not accidental. Ligature marks on her neck indicate strangulation. Sticks interrogates Denny about his whereabouts. The questioning is adversarial, and Denny leaves officially free but warned not to travel.

On the night of the dance, Anna's phone erupts with hundreds of threatening messages containing slurs, threats, and her personal information. She suspects the campaign was orchestrated by Mimi and the PTO. She disables her social media and files a police report but keeps the full scope of the harassment from Denny, fearing he would blame her for provoking the conflict.

Weeks after Anna's death, Denny finds "KILLER" scratched across his front door. He enters Anna's office and discovers her backup laptop, which contains 187 hateful messages and her correspondence with Mimi, none of which she ever shared with him.

The following summer, Anna joins Life Time, the health club where Hamilton's elite mothers gather. Mimi approaches with Karen Pistoulia and Ellen Wilson, two women from her inner circle. Anna sees what she believes is Mimi hip-checking Louisa into the pool, cutting her daughter's heel. She writes to the superintendent requesting Mimi's removal and finds herself iced out of the community. An anonymous letter arrives warning her she is "getting in over your head." Rather than retreating, Anna decides to run for PTO president herself. Researching the organization's history, she discovers that every president has been a member of the Chi Omega sorority.

Anna befriends Mary Langley, a younger mother from South Hamilton, who becomes her campaign strategist. They host a garden party and hold weekly sessions at Honeycomb, where Anna listens to mothers' grievances about the premium system. Di and Mary poll members and report that Anna has enough votes to win. At the garden party, however, Mimi grabs Anna's wrist and threatens her.

Denny discovers Anna was secretly running for PTO president. In her journals, he finds a final entry dated days before her death: "PTO. Cover operation. Secret society. College admission. PAY TO PLAY!!!" Di visits the house, and they sleep together. Afterward, Denny realizes Di has taken the notebook containing Anna's final entries. At the Hamilton Block Party, he discovers that Ellen Wilson is Sticks's sister, linking the lead investigator to Mimi's social circle. When Denny meets Sticks at a diner to share his findings, Sticks shuts him down. Days later, Denny's brakes fail on Storrow Drive in Boston. He finds brake fluid pooled on his garage floor.

Mary warns Anna that she saw Di dining with Mimi and Ellen, a meeting Di never mentioned. Anna defends Di and distances herself from Mary. After Anna's death, Denny visits Mary, who tells him that Di was always involved. She shows him a gold button from Anna's sweater that appeared in her mailbox as a warning. Sticks confronts Denny in the woods behind his house, whispering that "it's cold at the haul-out" in January, a threat echoing the circumstances of Anna's death.

Searching Anna's email, Denny finds messages from an anonymous sender called "Anon Mouse." The messages reveal that the PTO has operated since 1992 as a front for a secret society called the Generals, a network of Chi Omega sorority members who pay $100,000 annually for guaranteed college admissions, grade manipulation, and legal favors. Denny confronts Di, who confirms the women tampered with his brakes and warns him to forget everything. When he returns home, he finds Hank dead in the hallway, the front door forced open.

The novel depicts the night of Anna's murder in full. On a January evening, Anna drives to Di's house and is knocked unconscious. She wakes tied to a chair in the carriage house, surrounded by Mimi, Karen, Ellen, Di, and Mary. Mimi reveals the scope of the Generals' operation and explains that a former treasurer who tried to expose them was forced to relocate. Di admits she supported Anna's campaign only to control the narrative. Anna pleads to be released, but the women have decided. Mimi strangles Anna with her Gucci belt. Each woman takes a gold button from Anna's sweater as a binding memento. They drive the body to the river haul-out. Ellen calls Sticks, who arranges to redirect suspicion toward Denny. Ellen slips Anna's mother's engagement ring from her finger as a keepsake.

In the epilogue, Denny adopts a new dog and resolves to stay in Hamilton. The police return Anna's laptop, completely wiped. Denny notices a Boston Globe article about a woman's body found in another river, an implied reference to the former treasurer. He chooses silence and survival, recognizing that secrets are what keep small towns alive, and that even Anna had known this truth.