Jane, a single mother, is on her way to Pirriwee Public School, where her son Ziggy is starting kindergarten. On the way, she meets Madeline, another mother with a daughter of the same age. Madeline’s friend Celeste is also sending her twin sons, Max and Josh, to school. The two strike up a friendship with Jane. All three of them have their own problems: Madeline is resentful that her daughter from her previous marriage is growing close to her ex-husband's new wife, Bonnie. Celeste is physically abused by her rich banker husband, Perry. Jane is struggling with tracking down Ziggy's father, with whom she had a drunken, violent one-night stand. To make matters worse for her, Ziggy is accused of bullying a classmate on his first day of school.