Sarah Snook stars as Marissa Irvine in Peacock's limited series 'All Her Fault,' a thriller adaptation of Andrea Mara's novel where a family's life unravels after their son's kidnapping. In the finale, Marissa murders her husband Peter to protect herself and their child, a decision Snook discusses in a new interview. The series marks Snook's return to TV following her Emmy-winning role in 'Succession.'
Series Overview
'All Her Fault' is an eight-episode Peacock thriller created by Megan Gallagher, based on Andrea Mara's 2021 novel. Set in Chicago, it follows ultra-wealthy parents Marissa (Sarah Snook) and Peter Irvine (Jake Lacy), whose five-year-old son Milo (Duke McCloud) is kidnapped by their nanny Carrie (Sophia Lillis). The incident exposes dark family secrets, including Peter's fabricated backstory about his siblings Lia (Abby Elliott) and Brian (Daniel Monks), and a shocking revelation that Milo is not their biological son.
Five years prior, Peter and Marissa were in a car accident with Josie (Carrie's real name), who lost her infant. Peter switched the babies, claiming their newborn died. Carrie, discovering the truth through Milo's synesthesia, infiltrates the family by posing as a nanny for another parent, Jenny (Dakota Fanning).
The Twist Ending
In the finale, Peter kills Carrie's father and shoots Carrie to silence her after she records his crimes. Marissa, learning everything, faces a dilemma: revealing the truth would separate her from Milo. Exploiting Peter's soy allergy, Marissa kisses him after eating soy-laden food, causing anaphylaxis and his death. Detective Alcaraz (Michael Peña), sympathetic due to his own moral compromises, lets her go unpunished.
The series ends with Marissa and Jenny, both having eliminated their husbands, bonding over wine as their sons play, flipping the title's implication.
Snook's Insights
Snook, an executive producer, chose the role for its thriller elements, a departure from her 'Succession' character Shiv Roy. 'I've never really dived into this world,' she told Variety. Unlike the book's quieter poisoning, the show gives Marissa agency. Filmed in Melbourne between her stage runs in 'The Picture of Dorian Gray'—for which she won Olivier and Tony awards—Snook relished the 'harrowing moment' challenge.
She contrasts Marissa's maternal drive with Shiv's repression: 'Marissa definitely, confidently, wants to be a mum.' On the murder scene, Snook said, 'There's no turning back' after the kiss, emphasizing Marissa's need to remove Peter's influence. Future implications include Milo learning the truth and Marissa navigating grief and secrets with Jenny's support.
The series joins thrillers like 'Presumed Innocent' with its gasp-worthy reveals, now streaming on Peacock.