In suburban Michigan during the 1970s, the Lisbon family lives a seemingly idyllic life. The household is headed by a math teacher father and a strictly religious mother, and they have five attractive, enigmatic teenage daughters. The girls are sheltered and controlled by their parents, especially the mother who imposes stern rules, primarily focused on keeping the girls away from boys and maintaining their purity. The neighborhood boys are nevertheless fascinated by the sisters, especially the confident and charismatic Lux. After the youngest sister, Cecilia, attempts suicide, the Lisbon parents react by tightening their restrictions even further. Cecilia's subsequent successful suicide casts a gloomy pall over the household.

As the story unfolds, the community tries to comprehend the reasons behind Cecilia's act, with the local boys, in particular, struggling to understand the mysterious sisters. The boys’ obsession with the Lisbon daughters intensifies, leading to covert communications and brief, charged encounters with Lux. In the aftermath of Cecilia's death, the girls are pulled out of school, and their home life becomes more secluded, with the parents intent on protecting them from outside influences. This isolation serves only to deepen the chasm between the girls and the community while mirroring the growing tensions and despair within the Lisbon household itself.