Clive, his wife Betty, son Edward, daughter Victoria, mother-in- law Maud, governess Ellen and servant Joshua welcome the audience to his African home with a song paying tribute to England. Out of the song, the action of the play begins quickly. Clive returns home after spending the day managing the troubles among local tribes. Betty greets him and they swap stories about their days' experiences. When Clive learns that Joshua has been rude to Betty, he scolds Joshua. After this scolding, Clive greets the rest of his family, asking his children about their daily activities. After some pleasant discussion, the family welcomes Harry Bagley and Mrs. Saunders. Harry, an explorer, visits the family between expeditions. Mrs. Saunders, a widow, arrives exhausted, seeking protection from the natives. Betty and Harry flirt, revealing their attraction for one another. Later, Harry asks Joshua to have sex with him, and they leave for the barn together.
Clive chases Mrs. Saunders away from the house, and, after a brief argument, performs oral sex on her. To escape suspicion, they quickly return to the family's Christmas picnic, where Clive toasts the Queen. Clive and Harry toss a ball with Edward until Clive becomes frustrated with Edward's clumsiness. The game of ball gives way to a game of hide and seek, during which Edward and Harry reveal that they have a sexual history. Edward hopes to rekindle this relationship, but Harry is hesitant to approve. Meanwhile, Ellen professes her love for Betty. Betty, still smitten with Harry, dismisses Ellen's comments as ridiculous.
Later, Clive and the men flog the natives as the women wait inside the house. Mrs. Saunders, disapproving, leaves to find out what exactly the men are doing. Ellen becomes angry with Edward for playing with a doll and slaps him. When Clive returns from the flogging, Edward apologizes for playing with the doll and asks his father for forgiveness. When all but Betty and Clive leave for the verandah, Clive tells Betty that he knows about her affair with Harry. He lectures her on the necessity to resist lust, and then he forgives her.
As tension grows among the natives, Clive finds a moment alone with Harry to tell Harry about the increasing dangers. Harry makes a pass at Clive, and Clive reacts with horror, offended by Harry's homosexuality. Seeking a cure for Harry's perversity, Clive attempts to marry Harry to Mrs. Saunders. She refuses the offer. News that Joshua's parents have been killed by British troops distracts Clive momentarily, as he offers his condolences to Joshua. When Clive turns his attention back to Harry, he forces an engagement between Harry and Ellen. At the wedding party that follows, Mrs. Saunders announces that she is leaving, but before she can exit, Clive kisses her, prompting a fight between Mrs. Saunders and Betty. Disgusted at Mrs. Saunders behavior, Clive kicks her out of the house. When Clive goes to toast the newly engaged couple, Joshua raises a gun to shoot Clive. Edward sees this action, but does not warn Clive.
Roughly one hundred years later, Victoria appears in a London park on a winter afternoon with Lin and Lin's daughter Cathy. When Cathy exits to play elsewhere, Lin informs Victoria that she is a lesbian, and she asks Victoria to go to a movie with her. Edward, now a gardener, joins the two women, followed by Betty, who rambles at length about raising children. Betty also mentions that she is considering leaving Clive. Betty lets Cathy play with her jewelry. (Note: For the second act of the play, which takes place in London, actors switch roles. For instance, Betty in London is played by a different actor than Betty in Africa. See Characters.)
In the spring, Edward's lover Gerry comes to the park, where they argue about Gerry's lack of commitment. Gerry tells the audience about an affair he had with a stranger on a train. Victoria returns to the park with her husband Martin, who speaks at length about sex and his desire to please Victoria. Lin enters when Martin leaves and tells Victoria that her brother, a soldier, has died in Belfast. When Lin and Cathy get into a fight, they lose track of Victoria's son Tommy. A brief panic ensues before they find him. Gerry and Edward return, and Gerry breaks up with Edward.
Later, on a summer night, Lin, Victoria, and Edward come to the park to hold a ceremony for a sex goddess. Martin arrives, looking for Victoria, and they pull him into the beginnings of an orgy. Moments later, Lin's dead brother appears and relates the experience of his service in the army. Lin collapses when her brother disappears. Characters from Africa begin to make brief appearances, interacting with the London characters.
By late summer, Lin, Victoria, and Edward have moved in together. Betty has rediscovered the joy of masturbation. Gerry and Edward reconcile and make plans to go out some time. On a trip to get ice cream, the Dead Hand Gang assaults Cathy, bloodying her nose. Martin and Lin fight over who was supposed to be looking after Cathy. All but Gerry and Betty leave. In her discussion with Gerry, Betty comes to terms with the fact that Edward is homosexual. Betty from Africa returns and embraces the new Betty.