Lavinia is the adult daughter of the Mammons, a wealthy family living in New England at the tail end of the Civil War. Her suitor Brant is on his way, probably to propose again, while she awaits her beloved father Ezra's return from the front. Before Brant arrives, the family gardener warns her that Brant resembles her family, that he is probably the offspring of her uncle and and a nurse that used to work in the household. When Brant arrives, he angrily confirms the suspicion, adding that Lavinia's grandfather expelled his father from the family because he also loved the nurse, Brant's mother.
Later, Lavinia meets her mother Christine, accusing her of adultery with Brant. Christine admits that she hates her husband, but she agrees not to see Brant again if Lavinia will keep her secret. She later breaks her promise, plotting with Brant to kill Ezra with poison, making it look like a heart attack. Later, Christine riles Ezra to anger by revealing her affair with Brant. When his weak heart pains him, he asks for medicine but Christine gives him poison. With his dying breath, Ezra accuses Christine of poisoning him, just as Lavinia rushes into the room.
Lavinia's brother Orin arrives days later. He has an obsession with his mother and is disturbed by her rumored affair with Brant. She denies it vehemently, blaming it all on Lavinia's twisted mind. In a later meeting, Lavinia manages to convince Orin of her mother's relationship with Brant and the two wait to catch her in the act. Brant arrives in his ship later and Christine joins him on board. Lavinia and a horrified Orin follow and listen from outside their room as the couple plans to run away together. When his mother leaves, Orin hangs back and kills Brant, damaging the room so it looks like a robbery gone bad. Returning home, the brother and sister admit to Christine that they murdered Brant. Lavinia scorns her but Orin offers to run away with her. The shaken Christine enters the house and shoots herself.
A year passes and Orin and Lavinia have grown to perfectly resemble their dead parents. Orin believes that Christine's spirit has possessed Lavinia. He begins working on a book of all of their family's misdeeds. He jealously accuses his sister of taking a lover while they were on vacation and the two fight just like their parents used to. Orin drafts a letter to Lavinia and gives it to a servant saying that it must not be given to his sister until after his death. He then dramatically reveals his desire for his sister and shoots himself offstage.
The day of the funeral, Lavinia's suitor Peter asks for her hands in marriage, but Lavinia mistakes him for Brant. Horrified, she sends him away and decides to board herself up forever in the old house, with her secrets and her dead relatives' ghosts.
Best part of story, including ending:
I liked all the Freudian elements O'Neill put in the play. It's a retelling of an ancient Greek story, but this aspect updates it significantly.
Best scene in story:
I enjoyed the early scene where Christine's relationship with all the other characters in established. She's the most desired person in the play.
Opinion about the main character:
As interesting as Lavinia is, she has an air of unreality about her that kept me from experiencing the drama in anything but a cerebral way.