In the quiet suburb of Grosse Pointe, Michigan, a group of boys—now grown men—reminisce about their childhood memories of the five Lisbon sisters, aged between 13 and 17, during the summer of 1975. These sisters, Cecilia, Therese, Mary, Bonnie, and Lux, remain shrouded in mystery, constrained by the strict supervision of their parents, Ronald Lisbon, a math teacher, and his homemaker wife, Sara Lisbon. The girls become the subject of many conversations and dreams among the neighborhood boys, drawn to their enigmatic existence.
The poignant tale begins when the youngest sister, Cecilia, attempts to take her own life by slitting her wrists in a bathtub but survives. Her therapist, Dr. Horniker, advises her parents that this unfortunate act was an indication of her need for more socialization, particularly with boys. Despite this urgent recommendation, Mrs. Lisbon remains steadfast in protecting her daughters from the outside world. After much persuasion, Mr. Lisbon convinces her to host a chaperoned party for Cecilia, hoping to lift her spirits. Tragedy strikes when, after witnessing cruel teasing directed at a boy with Down syndrome, Cecilia escapes her struggles by leaping from her bedroom window, tragically impaling herself on a fence below.
The aftermath plunges the Lisbon family into an even deeper shell of isolation as the parents become increasingly vigilant over their remaining daughters. As the new school year begins, Lux, the most rebellious of the sisters, catches the eye of the charming Trip Fontaine, the school's heartthrob. In an effort to win Lux's affection, Trip spends time at the Lisbon household, charming the parents to let him escort Lux to the homecoming dance. What follows is a whirlwind of youthful exuberance as Lux and Trip indulge in a passionate encounter, but their romance is short-lived and fraught with heartache.
As punishment for breaking curfew, the sisters are confined, leading Lux to manifest her rebellious spirit in increasingly reckless ways. She engages in wild, late-night escapades atop their home, leaving the neighborhood boys intrigued yet helplessly watching from afar. After being secluded for what feels like an eternity, the girls send a final desperate message inviting the boys over, creating a flicker of hope for freedom.
However, when the boys arrive, they find Lux alone, smoking in the living room. As they wait, curiosity pulls them into the basement where they unearth the haunting realities of the sisters’ tragedy—Bonnie hanging lifelessly from the rafters and Mary in the kitchen, having succumbed to the gas oven. The chilling sequence culminates in the realization that Cecilia, Therese, Lux, Mary, and Bonnie had formed a devastating suicide pact.
Their lives forever altered by this dark event, the boys grapple with the haunting memories of the sisters as the Lisbon parents retreat from society, leaving behind a desolate home filled with remnants of their past lives. The neighborhood adults, shockingly indifferent or even mocking, move on as if nothing happened, while the boys are left tormented by unanswered questions about the girls they adored and the mystery surrounding their untimely deaths. Now middle-aged men, they confront the painful reality that the shadow of the Lisbon sisters will linger with them always, haunting their memories and thoughts.
