Father Willow stands and talks about the fact that he was once married, but cannot remember her former wife's name, at first calling her "Elizabeth," the name of his mother. As Willow struggles to remember the rest of it, Hester enters in her wedding dress. Everyone tries to get her to leave, but she refuses. "Have you ever been discarded, Elsie Kilbride?" Hester asks Mrs. Kilbride,"—the way I've been discarded. Do ya know what that feels like? To be flung on the ashpit and you still alive?"
Hester asks Carthage to come away with her, and Monica tries to get her to come to her house with her. When Hester refuses, Monica asks them to let Hester stay in the Bog of Cats. "A waste of time givin' chances to a tinker," Mrs Kilbride says, "All tinkers understands is the open road and where the next bottle of whiskey is comin' from." Monica immediately reminds Kilbride that her grandfather was a wandering tinsmith, little better than a tinker.
Carthage tells Hester to leave him alone once and for all, suggesting that her hateful displays have taken away any tender feeling he had for her. Hester pleads with them that her mother said she would come back for her, crying and saying, "I can't go till me mother comes. I'd hoped she'd have come before now and it wouldn't come to this." Josie offers to go with her mother, even though Carthage does not want her to go. Hester takes a bottle of wine and tells Josie she will come and get her later.
Act 3. Hester sits in a muddy wedding dress, while her house and the shed burns. Joseph, her dead brother, watches her. She talks about the fact that she has enacted her revenge on Carthage, as Joseph begins to sing a song about the Bog of Cats. Hester recognizes it as the song her mother made up for her, and she and Joseph begin to talk. Hester alludes to the fact that she is the one who slit Joseph's throat, saying, "I'd slit your throat again if ya stood here in front of me in flesh and bone."
The siblings argue about who their mother sang the song about the Bog of Cats to, and Hester begins to wail and sob for her mother. They discuss the fact that Carthage was there when Hester killed Joseph with a fishing knife, while they were in a rowboat. We learn that on that day, Hester and Joseph were in an argument about whether or not Hester was Josie's daughter, as Josie never mentioned Hester to Joseph. Hester tells Joseph that Carthage took Joseph's money, used it to buy land, and left Hester for another woman. We also learn that Josie (Hester's mother) told Hester's father that Hester had died at birth.
Monica calls for Hester and runs on, concerned about her house. Hester tells her it doesn't matter to her and they sit and drink. Monica talks about the fact that there was "somethin' cold and dead" about Hester's mother, except when she sang. Hester reiterates that she made a promise to herself to wait for her mother. They talk about how Hester has some dark powers at her disposal and Monica goes back to the wedding. Left alone, Hester calls out to the Ghost Fancier.
Suddenly, she's interrupted by Josie, who runs on to tell her she is going on Carthage and Caroline's honeymoon by the sea. Hester insists that she is not.
During the wedding ceremony, various characters suffer from lapses in their memory, or at least disputes about the past. When Mrs. Kilbride stands and tells the story of Carthage's childhood, a story in which he built a Calvary for her on her birthday, Carthage alleges to not remember ever doing such a thing. Also, in her remarks, and in the fact that she has worn white to her own son's wedding, we see that Mrs. Kilbride has blurred the lines between mother and lover. Immediately afterwards, Father Willow stands and talks about his own former wife, but accidentally uses his mother's name to describe her, and then struggles to remember his wife's name. Memory is very fluid in Carr's play, and just as there are blurs between the worlds of the past and the present, the living and the dead, there are blurs between generations, Freudian misrecognitions that illuminate the nature of inheritance.
A blurring also happens between the various brides. Caroline is wearing a wedding dress, Mrs. Kilbride wears her own white dress, Josie wears a Communion dress with a veil (all white), and finally, Hester enters dressed in her own wedding dress. Suddenly, the stage is flooded with brides, when there ought to be just one. The image of four women in white is also evocative of the realm of ghosts and the supernatural within the play. The wedding, which ought to be a celebration, becomes a strangely haunted territory, a power struggle, a turf war, and an exorcism of past wrongs and old tensions.
Hester's main problem, aside from the prophecy that she received at the beginning of the play, is her feelings of marginality at having been rejected from the world. Pushed to a point of desperation, feeling displaced and antagonized by almost everyone around her, Hester puts on her wedding dress and crashes the wedding of her ex. In this moment, she transforms her feelings of powerlessness and disenfranchisement into becoming a harbinger of doom, a witch-like arbiter of chaos who will not stop until she has seen justice served. While her actions are illogical, she forcefully imposes herself and baldly asks, "Have you ever been discarded, Elsie Kilbride?" Hester asks Mrs. Kilbride, "the way I've been discarded. Do ya know what that feels like? To be flung on the ashpit and you still alive?"
Hester becomes vulnerable when she explicitly talks about the reason she does not want to leave the Bog of Cats. She says that her mother said she would return for her, before abandoning her, and that she feels she must wait there until her mother returns. On the verge of tears, she pleads with the wedding guests to let her stay and wait for her mother, but they believe she is just ranting and raving. Yet again, Hester's stubbornness and aggression are directly connected to the pain she feels having lost her mother. She is in an arrested state, waiting for the mother who abandoned her to return and make amends for her neglect.
A shocking revelation occurs, in which we learn that Hester is the one who slit her brother Joseph's throat. In a fit of passion, she used a fishing knife to kill him at age 18, and Carthage took his money to buy the land from Hester. She admits to Joseph's ghost that she committed this horrible act because he stood between her and her mother Josie's love. In this revelation, we realize the extent of Hester's dark psyche, that it has led her to commit acts of murder. And add to that the fact that she reveals this while sitting outside her old house, which she just set on fire.