Whitney is the co-leader of the West Hollywood Moms' Club and operates a talent agency from her gated community home. Driven by a need to maintain her family's affluent lifestyle, she secretly manages the financial fallout of her husband's gambling addiction. She works tirelessly to protect her carefully constructed image while managing the chaotic aftermath of her best friend's death.

Brooke is a relatively new mother who feels like an outsider in the exclusive Moms' Club. Her life is in freefall after her wife, Abby, abruptly demands a divorce and restricts her access to their infant son. Struggling with trauma and profound isolation, Brooke's unusually calm demeanor during emergencies makes her an immediate suspect in the eyes of her peers.

Jade is a seemingly supportive and grounded member of the Moms' Club. She quietly manages her family's dire financial struggles and relies heavily on her friends to maintain her suburban lifestyle. Married to an unemployed husband, she feels constant pressure to keep up appearances and uses her role as a peacemaker to secure her place in the group.

Kiersten is the charismatic, supposedly flawless head of the West Hollywood Moms' Club. Before her sudden death at a party, she excelled at projecting an image of perfect domesticity and wealth. Her passing initiates a homicide investigation that slowly uncovers the intense pressures and hidden rivalries within her elite social circle.

Abby is Brooke's estranged wife who abruptly ends their marriage to pursue a new relationship. Emotionally detached and focused on her own interests, she takes aggressive steps to secure distance from Brooke. She restricts Brooke's access to their infant son, Julian, citing concerns over Brooke's mental health.

Colin is Whitney's charming but irresponsible husband. He struggles with a gambling addiction that routinely jeopardizes his family's financial stability. He largely allows Whitney to handle the fallout from his mistakes while he seeks validation elsewhere.

Ryan is Jade's unemployed husband. He spends much of his time playing video games and avoiding household responsibilities, leaving Jade to handle their family and precarious financial situation entirely on her own.

Tommy is Kiersten's devoted husband, left suddenly widowed after the party. He relies heavily on the support of his friends to process the immediate shock and grief of losing his wife.

Detective Perez is the lead investigator assigned to Kiersten's case. She closely questions the women, working to pierce through their polished facades to uncover the tensions and inconsistencies in their overlapping stories.

Natasha is a member of the West Hollywood Moms' Club who first discovers Kiersten in the water. She participates in the group's ongoing text chains and enforces its competitive social norms.

Colleen is a member of the Moms' Club who helps pull Kiersten from the water. She contributes to the group's collective reactions and rising suspicions following the tragedy.

Taylor is another member of the insular Moms' Club who aligns with the group's judgmental dynamics. She participates in the emergency gatherings where the women attempt to synchronize their stories for the police.

Julian is the infant son of Brooke and Abby. He becomes a central point of conflict when Abby takes him away from Brooke, sparking a desperate custody battle.

Liza is Abby's new, younger girlfriend. Her relationship with Abby serves as the catalyst for Brooke's emotional breakdown and subsequent social exile.

Lily is Jade and Ryan's older daughter. She is used by her mother to garner sympathy and financial support from the other women in the neighborhood.

Iris is Jade and Ryan's infant daughter. She is frequently cared for by the other mothers, including Whitney, when Jade is overwhelmed.

Rinley is the young daughter of Kiersten and Tommy McCann. Her existence is central to her parents' projection of a perfect family life.