The play opens with Beverly Weston delivering a monologue about poetry and suicide, a foreshadowing of the events to come. He then interviews Johnna, a young Cheyenne woman, for the position of live-in caregiver for his wife Violet, who is addicted to painkillers after being diagnosed with mouth cancer. Violet comes downstairs, hopped up on pills, as Beverly tells Johnna that he drinks and his wife takes pills. He hires Johnna once Violet goes back upstairs.
A few weeks later Beverly goes missing and members of the Weston family come to Violet’s house to comfort her while the police search for Beverly. Violet's daughter Ivy arrives first with Violet’s sister Mattie Fae and her husband Charlie. Barbara, another daughter, her husband, Bill, and Barbara’s 14-year-old daughter, Jean, arrive from Boulder, Colorado shortly after. The family fears that their patriarch has taken his own life. Barbara and Violet almost instantly get into an argument as they have had a strained relationship for years. Later that night Johnna and Jean connect when Johnna allows Jean to smoke marijuana in her attic room. We learn that Barbara’s husband Bill has been having an affair with a student at the university where he teaches and they are trying to hide their separation from the rest of the family. Early the next morning at 5 AM, Sheriff Gilbeau, an old flame of Barbara's from high school, comes to the house to reveal that Beverly’s body has been found in the lake, drowned.
After Beverly's funeral the family returns home to a dinner, where arguments erupt. Karen, Ivy and Barbara’s sister, has come into town with her fiancé, Steve, who ends up catching Jean smoking pot and offers to share some with her. He’s creepy and flirts with Jean even though she's only a teenager. Before the meal begins, we learn that Ivy, the consummate singleton, is having an affair with her meek cousin, Little Charles, but no one in the family knows.
Little Charles has overslept and missed the funeral, and while his father is forgiving, his mother Mattie Fae is very hard on him. During the meal, Violet talks about Beverly’s will in front of everyone which turns into a blowout argument after Violet reveals Bill and Barbara’s marital issues in front of everyone. The argument turns into physical violence when Barbara attacks her mother and insists that she's "running things now." Barbara orders everyone to go on a pill raid so that her mother doesn’t have the opportunity to get high again.
The last act begins several hours after the fight but tension is still high. Ivy reveals to her sisters that she and Little Charles are planning to run away to New York and leave Violet behind. Violet enters, more coherent than earlier, and tells her girls an awful story from her childhood. After the story Barbara and Violet apologize to each other.
Later, Mattie Fae sees her son and Ivy share a moment and begins to berate him. After Charles and Ivy leave, Barbara reveals to Mattie Fae that Little Charles and Ivy are having a love affair. Mattie Fae confesses to her niece that Little Charles is not Ivy’s cousin, but her half-brother, the result of an affair that she and Beverly had years ago. Mattie Fae refuses to tell either of them and the responsibility is left to Barbara, who knows that it will destroy Ivy.
During the night, Steve molests Jean, but is apprehended by Johnna, who comes after him with a skillet. The noise awakens everyone and leads to a brutal fight between Jean and her parents. Karen chooses to leave with Steve and blames the incident on Jean. Bill decides to take Jean home to Boulder and tells Barbara that he is leaving her.
Two weeks pass and Barbara is still at the house, drinking to excess. Barbara attempts to come on to Sheriff Gilbeau, who tells her that he can find out if Beverly received any calls at the motel he stayed at on the nights before killing himself.
Several days after this, Ivy comes to have dinner with Barbara and Violet to announce that she and Little Charles are in love, but before she can, Violet reveals that Little Charles is her brother. Violet says that she’s always known that Mattie Fae and Beverly had an affair that produced Charles. Ivy is distraught and says she will never tell Little Charles and they are going to move to New York anyway. In a final argument, Violet blames Barbara for her father’s suicide. Violet then says that the suicide could’ve been prevented because she knew the motel Beverly was staying in the night he left. Barbara leaves her for the last time. The play ends with Johnna and Violet alone in the house together as Johnna sings a T.S. Eliot poem to Violet.