Set in Santa Barbara, the film follows Dorothea Fields (Annette Bening), a determined single mother in her mid-50s who is raising her adolescent son, Jamie (newcomer Lucas Jade Zumann, in a breakout performance) at a moment brimming with cultural change and rebellion. Dorothea enlists the help of two younger women in Jamie's upbringing - via Abbie (Greta Gerwig), a free-spirited punk artist living as a boarder in the Fields' home, and Julie (Elle Fanning), a savvy and provocative teenage neighbor.