In an affluent British household, the wealthy Birling family is celebrating the engagement of their daughter, Sheila, to Gerald Croft. Their celebration is abruptly interrupted by the arrival of a stern and mysterious Inspector. He informs them that a young working-class woman named Eva Smith has committed suicide. The Inspector methodically questions each member of the family, revealing that they all have connections to Eva and may have played a part in driving her to despair. Each revelation exposes the characters' prejudices, secrets, and moral failings, which they had conveniently ignored until confronted.

As the Inspector delves deeper, tensions rise and defenses crumble. Arthur Birling's arrogant dismissal of responsibility is contrasted with the others' variety of responses, from guilt to bewilderment. The family's initial cohesion fractures as accusations and confessions flow. Through the Inspector's probing, the veneer of their respectability is peeled away, uncovering selfishness and hypocrisy. The story builds into a moral inquiry that questions societal values and individual accountability, leaving the family—and the audience—to grapple with the weight of their actions.