In An Inspector Calls, J.B. Priestley presents an unconventional approach to the traditional whodunit of detective fiction, resisting the trope in which an investigator interviews suspects to determine which character committed the crime, often a murder. Instead, the guiding mystery of Priestley’s play is not who killed the young woman, Eva (a.k.a Daisy), but how each member of the Birling family contributed to her suicide. By adopting aspects of mysteries, Priestley creates a work that examines collective, capitalist guilt. The play, as events unfold, suggests that an empowered class exploits the underclass without consideration of consequences for its exploitation. The Birling family’s collective guilt conveys Priestley’s message that it is the social duty of every human being to examine the impact of any action on others and to care for and help them, without self-consideration.

The play’s inciting incident occurs when Inspector Goole arrives at the Birling residence to question the family about the young woman’s suicide. Strangely, the Inspector does not ask questions about what they know about her death. His questions, instead, prompt each family member to struggle with and eventually face guilt for Eva/Daisy’s death. By using the Inspector to draw forth the characters’ emerging internal conflicts around responsibility, Priestley highlights how social status and affluence can blind people to others’ suffering. As the play moves on, the Birling family and Gerald begin gradually to accept their roles and, therefore, accountabilities in the young woman’s downfall.

The events of the rising action reveal how each member of the Birling family has negatively affected Eva/Daisy. The Inspector’s questioning unravels the mystery of how each family member has used social standing, influence, and power over others without personal consequence, devastating the young woman’s life. Arthur and Sheila ended her employment because she dared to strike for higher wages at the factory. Gerald exploited her sexually by having an affair with her after meeting her in a bar, knowing that his wealth and status ultimately would protect him. Sybil, as a matter of blaming the victim, refused to provide the homeless and pregnant Eva/Daisy with charity when she sought aid, although it is later revealed that her family is to blame for her condition. Each of these events, as the plot develops, highlights ways that greed coupled with the prerogatives of class victimize the poor and vulnerable. Arguably, if even one family member had acted kindly toward the woman, she might not have been driven to end her life.

As the play approaches its climax, the Inspector’s questioning focuses on Eric Birling, the likely heir to the family name and fortune, drawing attention to his apparent alcoholism. Priestley uses alcohol as a motif throughout the play, a symbolic catalyst for upper class abuse of the working class and a sign of dissipation. Alcohol is involved when both Gerald and Eric start their affairs with Eva/Daisy, and Eric’s drunkenness is a way for him to escape a sense of culpability for her situation. At the play’s climax, the family learns that Eric is likely the father of Eva/Daisy’s child and that he has been stealing money from the family business to help her—a matter of avoiding scandal. Arthur and Sybil worry, nevertheless, that a public scandal is likely, though they worry not because they had failed to help their grandchild but because of the negative effects it might have on the family’s reputation. This self-serving reaction epitomizes Priestley’s message about the inhumane treatment of the underclasses in a capitalist society. 

After the Inspector’s departure, during the plot’s falling action, members of the family blame each other for the potentially scandalous situation in which they find themselves. Priestley's genius lies in the twists that come to the surface as the play draws toward its conclusion. Sheila does offer glimpses of caring and compassion for Eva/Daisy when she criticizes her parents for worrying about their reputation rather than their treatment of the young woman. Gerald introduces an ambiguity by suggesting that the whole inquiry may have been a hoax or that there may have been more than one woman; Inspector Goole, after all, had never shown the picture to everyone at the same time. Priestley, by introducing doubt, is able to shift attention from the play’s specific events to broader questions about the treatment of all working-class people at the hands of empowered and wealthy families like the Birlings. 

At the play’s resolution, the group concludes that the investigation may have been a prank, and most of the family, especially Arthur, is relieved that their actions will stay private. Society, they assume, will not know of their indiscretions. However, they get a call that a young woman has committed suicide, and are told that an inspector is coming to their house for an inquiry. Their collective guilt, Priestly implies, will come to light after all. In the end, he suggests that there is no hiding when people abuse and mistreat the poor and vulnerable. The only way for society to flourish is for everyone to consider the common good, rather than personal or familial interests. Individual actions, he makes clear, have collective consequences.