All Her Fault sees a family and neighbourhood put to the ultimate test when a young boy suddenly goes missing.

Marissa Irvine believes she left her son in the capable hands of fellow school mother, Jenny, for an after-school playdate. But when she comes to collect him, she discovers that not only is Milo not at the address they said, the woman who lives there has no idea who Milo or Jenny are.

With the disappearance sending the Irvine family, and the local rumour mill, spiralling, it’s up to detectives to discover what happened to him before it’s too late.

But as the investigation continues and people dig deeper, long hidden truths are set to come to the surface for everyone, and their lives may never be the same.

Here are the key players in this labyrinthine mystery.

Played by: Sarah Snook (Succession, The Dressmaker)

Marissa Irvine is a wealth management specialist with her own business and a happy life. She adores her son Milo, and is content with her small but full world, so when she bonds with Jenny Kaminski at school, she’s pleasantly surprised. But all that changes when she goes to pick Milo up from Jenny’s house, only to discover that she’s been given the wrong address, and Milo’s not there… Now she’s got a fight on her hands, and people should know better than to cross a Mama Bear and her cub.

Played by: Jake Lacy (Apples Never Fall, The White Lotus)

Peter Irvine is a financier and feels like he leads the perfect life – he has a great house, a great job, a happy marriage, a happy child, and even a close relationship with his two siblings, Lia and Brian, whom he looks after. Peter thrives when he feels needed but finds himself at a loss with his own feelings when he’s not. This is never clearer than when Milo goes missing, and he feels his perfect world begin to crumble.

Played by: Dakota Fanning (Ripley, The Equalizer 3)

Jenny Kaminski is a career-driven woman who works at a publishing house. Her son, Jacob, is in the same class as Milo at school. While she has a nanny, she likes to be there for Milo as much as possible but is often pulled into the city for meetings. She is who Marissa believes she is leaving Milo with on the day that he goes missing, and as a result is left feeling guilty and responsible for his disappearance.

Played by: Thomas Cocquerel (The Gilded Age, Safe Home)

Richie is Jenny’s husband and works as a schoolteacher. He prides himself on having a carefree nature in and out of class, but that often comes at the detriment of his marriage. He takes pride in his work, and loves his son Jacob, but also appreciates his own space.

Played by: Abby Elliott (The Bear, Saturday Night Live)

Lia is Peter’s younger sister, and according to him has always had a turbulent nature. Despite this, she is extremely caring and loves Marissa and Milo. While her relationship with Peter can at times be contentious, she is really close to Brian and often wants to be there to take care of him. While she may have a reputation of being chaotic, Lia will go to bat to defend her family in whatever way she can.

Played by: Daniel Monks (Ricky Stanicky, Kaos)

Brian Irvine is Peter’s younger brother. After an accident as a child left him with a spinal injury, he has difficulty walking – though Peter encourages him to fight through it. Living at a specially built studio at Marissa and Peter’s house, and being set up with a job by Peter, he feels indebted to his brother. When Milo goes missing, he wants to do everything he can to help, even if it hurts him to do so.

Played by: Jay Ellis (Freaky Tales, Insecure, Top Gun: Maverick)

Colin is Marissa’s best friend and business partner, and one of the first people she calls when she discovers that Milo is missing. He has a friendly relationship with everyone in the family, though has a past that means Peter keeps him somewhat at arm's length. He is extremely loyal to Marissa and wants to help in the investigation anyway he can.

Played by: Michael Peña (Unstoppable, Ant-Man)

Detective Alcaras is the leading detective on the case. He is empathetic and friendly, and is extremely strait-laced, making sure everything is done to the utmost professionalism. Away from the case, he is a devoted dad to his 13-year-old son, Sam, who has Williams Syndrome. He is married to wife Casey, who works at the local hospital. Despite their demanding jobs, Sam remains the number one priority, no matter what.

Played by: Johnny Carr (Wellmania, The Survivors)

Detective Greco is Alcaras’ partner and is just as by-the-book. However, he has a little less experience than Alcaras does, which is both a benefit and hindrance to him. While Alcaras is making sure Greco is learning new things, Greco is able to keep himself more distanced from the case than Alcaras does.

Played by: Kartiah Vergara (Ticket to Paradise, Dora the Explorer: The Lost City of Gold)

Ana is Marissa and Peter’s nanny, who started working with the couple just a few months before Milo’s disappearance. She makes sure he gets picked up from school, takes him to the park and for milkshakes, and even tends to him when the Irvines are around.

Played by: Sophia Lillis (IT, I Am Not Okay with This)

Carrie Finch is Jenny and Richie’s live-in nanny, looking after Jacob during hours that Jenny has to work. She is adored by Jacob, who loves playing peekaboo with her, and is also liked by other kids and nannies alike. She joined the family six months before the events of the series.