Agatha Weiss makes her way to Los Angeles, enlisting the help of Jerome—a limousine driver—to take her to the location of her childhood home, once belonging to the former child star Benjie Weiss. Agatha bears profound scars on her face and body due to a past tragedy, necessitating a heavy regimen of medication. Meanwhile, Benjie, in a compassionate gesture, visits a young girl in the hospital battling non-Hodgkin lymphoma, only to be haunted by her spirit after she sadly passes away. His father, Dr. Stafford Weiss, a television psychologist, treats Havana Segrand, an aging actress navigating her trauma linked to her deceased mother, who was also in the film industry.
Havana's agent struggles to secure her a role in a remake of her mother’s iconic film, Stolen Waters, while Havana contends with frequent hallucinations of her younger self. As Benjie negotiates a comeback role post-rehabilitation alongside his mother, Cristina, the narrative intertwines when Carrie Fisher urges Havana to hire Agatha as her personal assistant, having met her through Twitter. The budding romance between Agatha and Jerome complicates further, as Agatha is Benjie’s sister, returning to a family that has ostracized her.
Utilizing her connection to Havana's project to infiltrate the film's production lot, Agatha makes a bold move to visit Benjie on his set. There, she reveals the dark truth about her past—that she unintentionally caused the fire which once nearly claimed his life. Stafford, upon discovering Agatha’s return, confronts her with financial coercion, demanding she leave L.A. to avoid jeopardizing everything.
Struggling with his sobriety, Benjie succumbs to the allure of GHB, which leads to a tragic incident where he accidentally injures a dog belonging to his friend. Agatha, seeking answers, confronts Cristina and learns about their shocking familial connection—an incestuous bond that casts a shadow over their lives. In a fit of rage, Stafford attacks Agatha when she reveals her knowledge of their family history, showcasing the deep-seated dysfunction within their home.
Meanwhile, Benjie is plagued by hallucinations, culminating in a disturbing on-set encounter with a young co-star. In a moment of uncontrollable anger, he nearly strangles her, placing his career in jeopardy. Amidst the chaos, Havana entices Jerome in her lavish car, much to Agatha's distress, leading to an explosive confrontation where Agatha, overwhelmed with rage, kills Havana in a moment of frenzy.
In the wake of these tumultuous events, a desperate Benjie seeks out Agatha. They share a heavy moment, with Agatha revealing their mother’s wedding ring and urging him to retrieve their father's. The tragedy culminates when Stafford witnesses Cristina engulfed in flames, leading to a horrifying act where he pushes her into the pool to end her suffering. In the aftermath, Benjie finds his father in a state of shock and, during a final reunion, he and Agatha crudely replicate a wedding ceremony using their parents' rings.
In a tragic decision, the siblings consume a dangerous amount of Agatha’s medication in an act of mutual despair, lying together under the vast sky, inviting the finality they believe ends their suffering together.
