Peacock’s psychological thriller All Her Fault, starring Sarah Snook, hooks viewers with every parent’s worst nightmare: a missing child. But as the investigation into five-year-old Milo’s disappearance unravels, the series reveals a plot so dark and deep that it makes the initial crime look simple.
The show isn’t just a kidnapping mystery; it’s a scathing critique of modern motherhood, the weaponized incompetence of husbands, and the moral rot hidden beneath the polished veneer of wealthy suburbia. The title itself—All Her Fault—is a pointed commentary on society’s eagerness to blame the mother.
Here is the definitive explanation of the ending, the shocking baby swap twist, Peter’s final punishment, and the survival kit needed for a life lived under perpetual, high-stakes scrutiny.
The Crime That Made the Kidnapping Inevitable
The initial plot—Marissa Irvine (Sarah Snook) sending her son Milo on a playdate that turns out to be a trap set by the nanny, Carrie Finch (Sophia Lillis)—is only the surface layer. The series is powered by the ultimate reveal that makes Carrie’s crime tragically complex:
The Shocking Baby Swap Twist
The series reveals that Peter Irvine (Jake Lacy), Marissa’s outwardly supportive but secretly manipulative husband, is responsible for a crime years in the making.
- The Accident: Years ago, Marissa and Peter were involved in a car accident with Carrie. Marissa was unconscious. Her baby died on impact. Carrie’s baby, however, survived.
- The Switch: Peter, desperate to protect his family life and Marissa from the trauma, swapped the two babies, placing Carrie’s surviving child into his own car seat, and pretending the baby was the real Milo.
- The Truth: Milo, the child Marissa has raised and loves, is Carrie’s biological son. Carrie recognized Peter and, driven by a desperate desire for the son she lost (not knowing he was the one she was trying to kidnap), engineered the playdate to take him back.
This revelation transforms the show from a simple thriller into a Greek tragedy. Marissa is forced to confront the fact that her entire family foundation is built on her husband’s horrifying secret, a secret that requires a flawless mask of perfection to maintain.
The Beauty of High-Stress Suburbia: Maintaining the Façade
The women of All Her Fault—Marissa, the high-powered wealth manager, and Jenny (Dakota Fanning), the publishing exec—are the picture of affluence. Their flawless appearances are part of the facade they maintain to ward off judgment. When you’re constantly scrutinized, your beauty routine needs to perform under extreme emotional duress.
- The Concealer of Secrets: For long nights of panic and anxiety, nothing betrays stress more than tired eyes. A high-coverage, non-creasing concealer is the ultimate secret keeper. The Hourglass® Vanish™ Airbrush Concealer is designed to eliminate dark circles and blemishes, ensuring no one can see the devastation beneath the surface.
- A Touch of Color for Life: To counter the paleness of constant worry, a quick swipe of healthy color is essential. We recommend the beautiful, buildable NARS Afterglow Liquid Blush, which delivers a natural, dewy glow that makes the wearer look rested and put-together, even when they’re not.
- Skincare for Trauma: High-level stress accelerates aging. For Marissa’s character to maintain her youthful, sharp look, an intensive anti-aging serum is a daily non-negotiable. The La Roche-Posay Retinol B3 Serum – Pure Retinol + Vitamin B3 provides a powerful evening ritual to repair and restore the skin barrier.
The Final Justice: Who Was Really at Fault?
The ending delivers the ultimate dramatic climax, holding Peter accountable not just for the baby swap, but for the subsequent murders of Carrie and the others involved.
Peter’s Final Fate
Marissa learns the full scope of Peter’s violent, controlling actions. She is faced with an impossible choice: report Peter, risk the truth coming out, and potentially lose Milo (Carrie’s son) forever; or stay silent, become complicit, and live with a murderer.
Marissa chooses her son. She keeps Peter’s confession a secret, determined to protect the only family she knows.
The Twist: Six months later, Peter dies on vacation in Spain from a severe allergic reaction to shellfish. News reports state that Marissa was unable to find his EpiPen in time.
The show makes it clear that Peter’s death was not officially her fault, but it heavily insinuates that Marissa intentionally withheld the EpiPen, freeing herself and Milo from the monster she married. She ends the show as the quiet architect of her own justice, finally seizing control of her life and her son’s future.
Marissa’s Ultimate Survival Kit
Marissa’s actions are fueled by a desperate, protective maternal love. To navigate the anxiety and stress of living with a deadly secret, her self-care routine is paramount.
- Lip Comfort for Quiet Strength: In moments of high emotional turmoil, a soothing, familiar comfort is needed. Marissa’s look is polished but never overdone. A tinted, nourishing product like the rhode Peptide Lip Tint offers a subtle, caring enhancement while prioritizing lip health.
- The Sunscreen Shield: A wealthy suburban life involves constant outdoor activities—from school pickups to country club events. Protecting her skin from daily UV exposure is essential for maintaining her immaculate appearance. The La Roche-Posay Anthelios Mineral Sunscreen SPF 50 provides a high-level, elegant mineral defense.
- A Bronzed Escape: Despite the chaos, Marissa maintains the polished appearance of someone who can afford a break. A natural, healthy warmth is achieved with a sweep of the luxurious Gucci Poudre de Beauté Éclat Soleil Bronzing Powder, giving the illusion of a sunny getaway, even when she’s trapped in a nightmare.
In the end, All Her Fault asks if the fault lies with the mother who made a simple mistake, or with the narcissistic man who manipulated every life around him. The show’s answer is clear, even if Marissa’s final actions are morally gray: sometimes, the greatest crime is the one that sets you free.