Good Intentions Book Summary: A Thriller About Grief and Obsession
Introduction: What Marisa Walz’s Good Intentions Is About
On Valentine’s Day, a luxury event planner named Cady McKenna is staging a $50,000 sweet sixteen party when her phone begins ringing.
By the end of that night, her identical twin sister Dana is dead, and Cady is sitting in a hospital waiting room where another mother, Morgan Hess, learns her twelve-year-old son has also died.
Marisa Walz’s novel Good Intentions follows what Cady does with that grief.
Set across Chicago’s affluent suburbs, the book tracks a woman who inserts herself into a stranger’s life under false pretenses while carrying a secret about what she did that day.
TL;DR: The Quick Brief
A wealthy Chicago event planner loses her identical twin, fabricates a dead baby to join a grief support group, and stalks a grieving mother she met in a hospital waiting room.
The story is told entirely as a second-person confession addressed to the dead sister.
- Narrator: Cady McKenna, unreliable and increasingly delusional.
- Structure: 68 chapters of direct address to Dana, the deceased twin.
- Core engine: Guilt, envy, and codependency driving a slow unraveling.
- Ending: A suppressed hit-and-run reveal that reframes the entire book.
Who Appears in Good Intentions
| Character | Role |
|---|---|
| Cady McKenna | The narrator and protagonist, a thirty-three-year-old event planner running Eventually, LLC in suburban Chicago. |
| Dana Stoll | Cady’s identical twin sister, a high school guidance counselor in Downers Grove who dies in a Valentine’s Day car crash. |
| Matt McKenna | Cady’s husband, a commercial real estate developer facing fraud exposure through a former business partner. |
| Morgan Hess | A grieving mother and accounting analyst whose twelve-year-old son dies on Valentine’s Day. |
| Christopher Hess | Morgan’s twelve-year-old son, killed while riding his bicycle on Valentine’s Day. |
| Sean Stoll | Dana’s husband, a self-storage facility manager who chooses forgiveness over litigation. |
| William Fahey | The driver whose car collided with Dana’s and who stays with her as she dies. |
| Moira | The facilitator of a parent bereavement support group at Morton West High School. |
| Jamie | Cady’s assistant at Eventually, LLC, who keeps the business running until she resigns. |
| Ben | A tech project manager Cady contacts through a dating app while impersonating Morgan. |
| Alan Prescott | Matt’s former business partner, who forges documents and flees with investor funds. |
| Lisa and Jim Knudsen | Cady and Dana’s parents. |
| Gene Callahan | Cady’s therapist, who suggests she address her thoughts directly to Dana. |
Good Intentions Summary (Spoilers Ahead)
Spoiler warning: this section covers the plot, including the ending.
Cady McKenna is thirty-three, married to developer Matt McKenna, and runs a boutique event planning firm called Eventually, LLC. She is also inseparable from her identical twin, Dana, a guidance counselor in Downers Grove.
Weeks before Valentine’s Day, Dana announces she is pregnant. Cady, who has endured years of unsuccessful IVF and a recent miscarriage, reacts with envy and accuses Dana of breaking a childhood pact.
The sisters part on unresolved terms. On Valentine’s Day, Cady is running a client’s sweet sixteen party at a converted luxury bathhouse when calls begin coming in about a collision in Oak Park.
Cady reaches Rush Hospital and learns Dana, eight to ten weeks pregnant, has died. In the same waiting room, she watches Morgan Hess collapse on hearing that her twelve-year-old son Christopher is dead.
She also notices a dark-haired man in a green Patagonia jacket watching her. Cady’s grief is poisoned by guilt over how she and Dana last spoke.
Using hospital details and online searches, Cady finds Morgan’s address and begins parking outside her house for hours. She joins a parent bereavement group at Morton West High School led by a blunt facilitator named Moira.
Because the group is only for parents who have lost children, Cady invents a story. She claims she lost a ten-week-old baby girl named Dana as well as her twin sister on Valentine’s Day.
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Cady cultivates a Sunday-morning coffee friendship with Morgan. Meanwhile, her actual life comes apart: she abandons clients, ignores calls, and leaves her assistant Jamie to hold Eventually, LLC together alone.
She later accuses Jamie of an affair with Matt. Jamie reveals that Matt was only calling to cover for Cady’s absences, then resigns, effectively ending the business.
Matt has his own crisis. He was defrauded in a multi-million-dollar real estate deal by former colleague Alan Prescott, who forged documents and fled with investor money, exposing Matt to financial ruin and possible criminal liability.
The man in the green jacket reappears at Dana’s burial and is identified as William Fahey, the driver who collided with Dana’s car. Dana’s husband Sean and her parents choose to forgive him and forgo a civil lawsuit.
Cady remains furious. In one disturbing moment, she encounters William’s young son playing basketball and lures him away under the pretense of finding a lost dog before returning him safely.
Her boundary-crossing with Morgan escalates. Cady creates a dating profile for Morgan without her knowledge, chats with a man named Ben while impersonating her, and buys Morgan an expensive orange Hermès Birkin bag.
She invites Morgan over for a makeover, styles her until she resembles Cady and Dana, and presents the bag. Frightened by the intensity and the uncanny resemblance, Morgan flees.
Morgan then finds the fake dating profile, a cropped photo of her dead son, and evidence that Cady invented a deceased baby. She cuts all ties and demands Cady stay away from her and the group.
Morgan contacts Matt, who confronts Cady about the stalking, the fabricated baby, and the fake dating scheme. He packs his bags and leaves.
Cady also learns that her elderly dog Champ, missing for months, was hit by a car and died the night Matt searched for him, a fact he had concealed. Cady begins therapy with Gene Callahan.
Callahan suggests she voice her unspoken thoughts directly to Dana, framing the novel’s second-person narration as Cady’s internal monologue.
A year after Dana’s death, Cady organizes a celebratory memorial and re-founds her business as Grand Gestures, a non-profit event firm. William Fahey attends, asks for forgiveness, and Cady quietly accepts.
In the final chapter, Cady sits outside Morgan’s house for one last watch. She reveals the secret she has suppressed throughout the book.
On Valentine’s Day, driving frantically after hearing about Dana’s crash, Cady struck a twelve-year-old boy on a bicycle with orange handlebars at an intersection. She saw him lying motionless as an older woman with a dog rushed over, then drove away to reach Dana.
She closes by justifying her continued surveillance of Morgan, insisting she cannot abandon her because sometimes people must be helped no matter what.
The confession ends with her stating she knows today will not be the last time.
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Good Intentions: Book Details at a Glance
- Genre & Subgenre: Psychological Thriller / Domestic Suspense / Noir
- Core Narrative Tropes: Unreliable narrator, twisted twin dynamics, secret obsession and stalking, hidden hit-and-run, guilt-driven spiral
- Tone & Atmosphere: Dark, intimate, claustrophobic, melancholic, suspenseful
- Primary Conflict: Cady’s internal struggle with suppressed guilt, envy, and hit-and-run liability against her collapsing marriage, ruined business, and Morgan’s rejection
- Pacing Style: Slow-burn psychological suspense escalating through layered secrets to a confrontation and final twist
- Structure: 68 chapters told as continuous second-person address to the deceased twin, Dana
- Publisher: St. Martin’s Press
- Publication Date: February 3, 2026
- Pages: 336
- ISBN-10: 1250397405
- ISBN-13: 978-1250397409
What the Novel Examines
| Theme | How the Book Presents It |
|---|---|
| Grief and Non-Linear Healing | Support group members, Morgan, and Cady’s parents each grieve differently, and Moira tells the group there is no wrong way to do it. |
| Twinship, Codependency, and Identity | Cady describes building her world small around Dana, and Dana’s death leaves her without a separate sense of self. |
| Guilt, Secrets, and Compounding Deception | Cady fabricates a dead child, creates a fake dating profile, and conceals her role in a fatal hit-and-run. |
| Good Intentions Versus Delusion | Cady repeatedly frames stalking and manipulation as helping, telling Dana she has always had good intentions. |
| Control and Curation | A luxury event planner by trade, Cady stages real relationships the way she stages parties, including Morgan’s hair, makeup, and gifts. |
Books Like Good Intentions
- The Perfect Marriage by Jeneva Rose — Fast-paced domestic suspense with unpolished characters and a late narrative turn, and it is endorsed on the cover of Good Intentions.
- The Girl on the Train by Paula Hawkins — A grief-stricken, unreliable female narrator consumed by compulsion, voyeurism, and distorted memory.
- Verity by Colleen Hoover — Dark obsession and secret written confessions, noted on Morgan’s reading shelf within the text.
- The Silent Patient by Alex Michaelides — Psychological trauma, suppressed secrets, and a climactic reveal.
- The Push by Ashley Audrain — Psychological unraveling tied to maternal grief, guilt, and family undercurrents.
