All Her Fault starts with the pedal to the metal — and with a remarkable showcase for Sarah Snook. Marissa Irvine receives a message telling her to pick up her son, Milo, who is supposedly playing at the house of Jacob, a classmate from school. But when she arrives at the address, she is met by Esther, the homeowner, who explains that there must be a mistake: no children live there, and certainly no one named Jenny, the supposed mother of Milo’s friend. The phone number used to arrange the playdate is disconnected, and it quickly becomes clear that Jacob is with another guardian. When Marissa finally reaches Jenny, the situation grows even more disturbing: she never arranged any playdate between the boys.

Not even Marissa’s husband, Peter, knows where Milo is. Within minutes, the worst is confirmed: the child is missing. We barely have ten minutes of the episode before we are as anguished as she is. The drama reaches its peak almost immediately — and never lets go.

The police are called, and Detectives Alcaras and Greco take over the investigation. A few details stand out from the start: the family’s nanny, Ana Garcia, hired months earlier through a specialized website, is off duty and not answering her phone. As far as anyone knows, she traveled to attend a wedding.

Because the Irvines are wealthy, the assumption is immediate: kidnapping. But Marissa begins to punish herself as her own mistakes become increasingly clear — she didn’t double-check the number, had never been to Jenny’s house, and never questioned anything. Guilt seeps in even before evidence does.

Elsewhere in Chicago, Jenny talks to her husband, Richie, expressing empathy for Marissa’s ordeal while insisting that he stick to their agreement and pick up their son from Sarah Larsen’s house. This parent organizes everything at school and also happens to be the resident gossip. Sarah, unsurprisingly, wastes no time criticizing Marissa’s lack of caution, suspects the nanny because she is an immigrant, and questions why Jenny’s name was used in the first place.

Two months earlier, the episode takes us back to the first day of school. Sarah appears as the model, hyper-demanding mother — the kind who makes women juggling motherhood and careers, like Jenny and Marissa, feel perpetually inadequate. In parallel, we see Ana Garcia filling out a security form, visibly uncertain. A woman approaches to help her. Her name is Carrie Finch. She says she is the Kaminskis’ nanny.

Back in the present, Ana becomes the prime suspect. Every possibility is examined: relatives, friends, anyone who might be involved. After an entire afternoon of phone calls, Marissa discovers that the nanny’s cellphone was left behind at home. Ana arrives later that night, and it quickly becomes clear that she is innocent.

Meanwhile, Jenny is in an important meeting, trying to secure a new client — a mystery novelist — when, predictably, Richie fails to hold up his end of the deal and doesn’t take care of their son. Jenny has to leave abruptly. When she gets home and sees the police, she panics. Then comes the crucial revelation: it was Carrie who picked Jacob up from school.

Jenny realizes she knows very little about the woman who has been caring for her own child. She, too, made mistakes. As the title suggests, everything seems to be someone’s fault — and everyone’s.

Tension escalates inside the Irvine family. Peter’s siblings, Lia and Brian, along with Colin, Marissa’s business partner, display a strange, almost suffocating intensity. Gradually, blame shifts toward Jenny, accused of negligence and, therefore, of enabling Milo’s disappearance.

Another jump in time, now ten days before the kidnapping: Jenny and Marissa meet at a school cocktail party. The toxic culture of perfect parenting resurfaces, causing Jenny to break down in tears. The two women connect over something seemingly trivial — they are wearing the same dress — and over a shared desire to escape the scrutiny of flawless mothers.

In the present, Jenny ignores warnings from Sarah and other parents and decides to go to the Irvines’ house to support Marissa. Alcaras and Greco reinforce that this was not a random mistake: there was intent. Milo’s tracker was destroyed.

Twenty-seven days later, the detectives’ investigation comes to include a murder.

Everyone involved — except Richie — becomes a suspect.

Who died?
Who killed them?
And, ultimately, why?