An Inspector Calls is a play in three acts, set in Brumley, an English manufacturing town, in 1912. Arthur Birling has convened a dinner for the engagement of his daughter, Sheila, to her boyfriend, Gerald Croft. Arthur and his wife Sybil seem happy, although Sybil is reserved at the meal. Eric, Sheila’s brother, drinks heavily and appears mildly upset. Gerald gives Sheila her ring, and Sheila and Sybil leave the room to try on wedding clothes. Eric goes upstairs. Arthur tells Gerald he knows the Croft family considers themselves social superiors of the Birlings, but that’s easily remedied, he says, as he expects a knighthood for his business successes. Gerald promises to relay the news to his mother. Eric returns, and Arthur gives the two young men advice about professional life, saying that people ought to look out for themselves and their families, and not fall prey to socialist propaganda about the collective good. Edna, the maid, announces that an Inspector Goole is here to speak to Arthur.

The Inspector, whom Arthur does not know despite his positions in local government, announces that a girl named Eva Smith has died of an apparent suicide. The Inspector asks Arthur if he knows anyone by that name. Arthur initially denies it, but after seeing a picture, he admits to employing Eva at his factory, and firing her when she incites a failed strike for higher wages. Arthur says he is not sorry for doing so, even though he is sad to hear of the girl’s death. Arthur believes that his foremost obligation is to his profits. When Sheila returns to the room, the Inspector begins interrogating her. It is revealed that Sheila got a girl fired from Milward’s, a local shop, for giving Sheila mean looks as she was trying on clothing. Sheila regrets to hear that the person she incriminated was none other than Eva Smith, and that she and Arthur are responsible, in part, for Eva’s poverty and suicide.

The Inspector turns to Gerald and asks if he knows someone named Daisy Renton. Sheila realizes, from Gerald’s expression, that Gerald knows this name. When all but Sheila and Gerald leave the room, Sheila accuses Gerald of having had an affair with Daisy Renton the previous summer. Gerald admits to this. He asks Sheila to hide this information from the Inspector, but she says it won’t be possible because the Inspector probably already knows. Act One ends.

Act Two begins with the same set. The Inspector questions Gerald about Daisy Renton, and Gerald admits to the affair in front of Sheila and her parents, Arthur and Sybil. Gerald is embarrassed by his indiscretion, but insists his concern for Daisy was authentic. Sheila wonders if she can forgive Gerald enough to continue their relationship. Gerald tells the Inspector he is going to leave for a walk.

The Inspector moves on to Sybil, who, on being questioned, says that she, as director of a charity, refused assistance to a pregnant woman. The Inspector tells them that the girl Sybil turned away was Eva Smith, or, as Gerald knew her, Daisy Renton. The Inspector also says that Gerald was not the one who got Eva pregnant. Sybil says she feels no regret, as Eva/Daisy had claimed she was pregnant but was not married to the child’s father. To this, Sybil responded that Eva/Daisy should ask the child’s father for money. Sybil blames the unnamed father for the situation, and for Eva/Daisy’s suicide. Sheila and Arthur tell Sybil to stop talking. In this moment, Sybil realizes that her son, Eric, must be the father of the child, since Eva/Daisy presented herself to the charity as “Mrs. Birling.” Eric returns to the room. Act Two ends.

In Act Three, with the same set, Eric admits to an affair with Eva/Daisy, and to a drinking problem that makes many of the details hazy. The Inspector demonstrates that each member of the Birling family, and Gerald, has played a part in Eva/Daisy’s suicide, and that all should consider themselves guilty. Before he leaves, the Inspector says that people must look out for one another, and that society is “one body.” The Inspector departs. Sheila, wracked with guilt, wonders aloud whether the Inspector is a member of the police force. The family puzzles this out, and when Gerald returns, he says he spoke to a sergeant outside who does not know of any Inspector with the name of Goole, the man who just visited the Birling home. Arthur believes that the family has been hoaxed, and that this is a good thing, since their misdeeds will not now result in public scandal. Sheila resents Arthur’s rationalization of the family’s behavior, and she says they are still guilty for Eva/Daisy’s death, even if the Inspector was not a genuine officer. Gerald, however, notes that no family member saw the picture of Eva/Daisy at the same time, and that the Inspector might have conflated the family’s stories by offering pictures of different women, and changing the names from Eva Smith to Daisy Renton.

Sheila wonders whether this would excuse everyone’s behavior, but it does not, as Gerald still committed his affair, Eric impregnated an unmarried girl, and Arthur and Sybil behaved uncharitably to young girls in need. Arthur calls the hospital and confirms that no self-inflicted deaths have been recorded for weeks. He says resolutely that Inspector Goole has tricked the family and that there is nothing to fear. Sheila worries aloud that Arthur will ignore the lessons the family was just beginning to learn. The phone rings, and Arthur answers. He alerts the family that a girl has been admitted to the hospital just now, and that her death is a suicide. As the play ends, Arthur relays to the family that a police inspector is headed to the house to begin an inquiry.