The film unfolds during a sweltering August in a rural district near Pawhuska, Oklahoma, just 60 miles Northwest of Tulsa. It centers around the deeply troubled Beverly Weston, an alcoholic former poet, who seeks the help of a young Cheyenne woman, Johnna, to serve as a live-in cook and caretaker for his fiercely independent wife, Violet, portrayed by the talented Meryl Streep, who is grappling with oral cancer and a substance abuse problem. Shortly after Johnna's arrival, Beverly mysteriously vanishes, prompting Violet to reach out to her estranged family for assistance.
Violet's sister, Mattie Fae, accompanied by her husband Charles Aiken, soon arrives to lend her support. Meanwhile, Ivy, Violet's middle daughter, the only one left in Oklahoma, and her eldest daughter, Barbara, a woman seemingly shaped by her mother's harshness, come together with their families in an atmosphere charged with unaddressed tension. Barbara, who has brought along her estranged husband Bill and their teenage daughter Jean, aims to maintain a façade of unity in the face of Violet's deteriorating health.
Tragedy strikes when the sheriff reports that Beverly has drowned, prompting the arrival of the youngest daughter, Karen, who walks in with her latest boyfriend, Steve Huberbrecht, a dubious businessman from Florida whom she introduces as her fiancé. A poignant moment occurs when Little Charles, Mattie Fae and Charles's awkward and insecure son, misses the funeral due to oversleeping. The strained dynamics within the family become glaringly evident as Ivy confides a secret to her sisters: she is romantically interested in her cousin, Little Charles, who is contemplating a move to New York. However, Ivy grapples with sadness as she shares her inability to bear children, a consequence of a prior hysterectomy, making her dream of marriage feel unreachable.
The situation escalates during a post-funeral dinner where the atmosphere is thick with emotions. Violet, under the influence of drugs, begins to unleash her cruel tongue, verbally assaulting her family members, culminating in a fiery clash with Barbara. Fueled by pent-up frustration over her mother's addiction, Barbara retaliates physically, forcing Violet to confront her dependency by confiscating her numerous pills. In an unexpected moment of clarity, Violet opens up about the pain inflicted upon her by her own mother—a Christmas when she was given old, decrepit men's boots instead of the cowgirl boots she desired, a lesson in cruelty that lingers in her memory.
As tensions rise, Little Charles musters the courage to share a song he composed for Ivy, but is interrupted by Mattie Fae’s harsh criticism, which finally pushes Charles to confront his wife about her lack of affection for their son. The situation spirals when Mattie Fae inadvertently reveals that Little Charles is also Beverly's illegitimate son, complicating Ivy's feelings further.
The plot thickens when a moment of intoxicated recklessness occurs between Steve and Jean. Their evening takes a dark turn as Steve attempts to assault Jean, leading to a courageous intervention by Johnna who attacks him with a shovel. The chaos awakens the rest of the family, culminating in a confrontation that sees Barbara slapping Jean, driving her into a panicked departure back to Colorado with her father, Bill. Karen, in denial about her failing relationship with Steve, also chooses to leave, locking herself in a cycle of unresolved issues.
In a heartfelt attempt to confide in her mother about her relationship with Little Charles, Ivy finds instead that Violet already knows the painful truth—that Charles is both her cousin and her brother. Heartbroken and disillusioned, Ivy vows never to return. The film reaches a tragic climax when Barbara learns that Violet was aware of Beverly's suffering but failed to act until it was too late, leading to his suicide. This revelation shatters Barbara's resolve as she realizes her mother cannot be saved.
The emotional weight of the family’s unraveling leaves Violet with only Johnna for companionship. In a moment of solitude, she begins to dance to the music, but her grief catches up, and she retreats in search of Johnna’s comfort. Meanwhile, Barbara, feeling the immense burden of her family’s dysfunction, drives alone through the plains, wrestling with tears as she contemplates her next steps, ultimately setting her sights westward towards an uncertain future.
