The tale of three mothers of first graders whose apparently perfect lives unravel to the point of murder.
In an affluent community, a suspicious death at an elementary school fundraiser draws attention to the friction amongst some of the mothers; Madeline and Celeste welcome Jane into their inner circle; battle lines are drawn after an incident.
Jane deflects Ziggy's questions about why they moved; Madeline is outraged over a slight from Renata; Celeste suggests that she and Perry should see a counselor; Nathan and Ed meet in hopes of smoothing out tensions between their wives.
Hoping to get under Renata's skin, Madeline organizes a trip to compete with Amabella's birthday party. After another argument, Celeste succumbs to Perry's charms before their first session with Dr. Amanda Reisman, a therapist. Madeline gets called for a meeting with Abigail's guidance counselor. Principal Nippal announces the theme for the Fall Gala Fundraiser. Later, Jane seeks Madeline's help with Ziggy's family tree project, and opens up about her past.
Nathan invites Madeline and Ed to a couples' dinner to discuss a "parenting paradigm" for Abigail. Celeste prepares for a city-council meeting about Madeline's play, and bristles at Perry's concerns about her returning to work. Jane meets with Ms. Barnes, Ziggy's teacher, who suggests her son be medically evaluated in light of further evidence of classroom bullying. While Madeline is confronted by a skeleton from her past, her internet sleuthing reveals a key player from Jane's past instead.
Madeline receives encouraging news about the play from her director, Joseph Bachman, but is left concerned by his newly icy demeanor. Principal Nippal and Ms. Barnes share their conclusions about Ziggy and Amabella with Jane. Celeste has a solo session with Dr. Reisma, who tries to get to the bottom of her relationship with Perry.
Madeline worries about the can of worms she's opened for Jane. Jane confronts Renata. Bonnie tells Nathan about a secret project Abigail has been working on. Meanwhile, Ed and Madeline have a frank conversation about the lack of passion in their marriage.
In the Season 1 finale, Celeste makes a bold move after another fight; Madeline deals with fallout from her past before the school's fall fund-raiser; and Jane learns who's really been hurting Amabella at school.
Following first-day-of-school events, Madeline is worried by Bonnie's behavior and, later, is shocked when Abigail says she doesn't want to go to college. Mary Louise, Celeste's mother-in-law, offers her unvarnished assessment of Madeline's character. Jane learns from her new coworker, Corey, that she's known in town as one of the "Monterey Five."
Renata faces an uncertain future when Gordon lands in legal trouble. Corey asks Jane out on a "practice" date. After a challenging therapy session with Dr. Reisman, Celeste opens up to Mary Louise about her relationship with Perry. Bonnie's mom, Elizabeth, arrives. Ed confronts Madeline about her secrets.
Mary Louise tries to get closer to Jane. Rather than address her troubles at home, Renata focuses her wrath on Principal Nippal. Madeline is forced to confront her issues at a couples therapy session with Dr. Reisman. Celeste remains conflicted by her memories of Perry.
Celeste accuses Mary Louise of overstepping boundaries with Jane. Renata endures a prying court hearing with Gordon. Jane opens up to Corey at Amabella's disco-themed birthday party. Madeline continues to try to make things right with Ed.
Renata deals with the fallout from Gordon's legal troubles and attempts to help Celeste. Bonnie relives painful memories from her past.
Celeste is blindsided by Mary Louise. Gordon continues to disappoint Renata. Bonnie contemplates a solution to her mother's suffering and her own ongoing guilt. Ed entertains an unusual proposition before catching Madeline in an unguarded moment. The Monterey Five feel the pressure of increased scrutiny of Perry's death.
Celeste questions Mary Louise about a tragic event from Perry's childhood; Madeline worries their lie is tearing the Monterey Five apart.
