Duke Vincentio appoints Angelo as deputy governor of Vienna and quietly departs the city.

Mistress Overdone informs Lucio that his friend Claudio has been arrested and faces execution for impregnating Juliet.

Claudio, being escorted to prison, asks Lucio to find his sister Isabella and beg Angelo for his life.

Isabella agrees to leave the convent and go plead before Angelo to spare her brother's life.

Isabella argues before Angelo that all humans are tempted by sin and therefore mortal judges must show mercy.

Angelo dismisses Isabella but asks her to return the following day, giving no indication of his true intentions.

Angelo propositions Isabella directly, offering to free Claudio if she gives up her virginity to him.

Isabella refuses Angelo's proposition and threatens to expose him publicly, but fears no one will believe her.

Vincentio, disguised as a friar, overhears Isabella tell Claudio about Angelo's offer and begins devising a counter-plan.

Vincentio brings Isabella to meet the abandoned Mariana and proposes using a bed trick to fool Angelo.

Isabella, Mariana, and Vincentio finalize their plan for Mariana to secretly enter Angelo's chamber in Isabella's place.

Angelo sends a written order to the prison demanding Claudio's execution despite his earlier promise to Isabella.

Isabella publicly accuses Angelo of corruption and murder before the returned Duke at the city gates.

Lucio accidentally exposes Vincentio by pulling off Friar Lodowick's hood during a scuffle at the trial.

Vincentio reveals Claudio is alive and proposes marriage to Isabella, but she does not respond.

Duke Vincentio appoints the strict Angelo as deputy governor and secretly remains in Vienna in disguise to observe the results. When Angelo sentences Claudio to death for premarital sex, Claudio's sister Isabella pleads for mercy, and Angelo corruptly propositions her in exchange for her brother's life. Isabella refuses, and the disguised Vincentio devises the bed trick, arranging for the abandoned Mariana to take Isabella's place in Angelo's chamber. Despite the plan, Angelo breaks his promise and orders Claudio's execution, leading Vincentio to secretly preserve Claudio's life using a substitute prisoner's head. At the city gates, Vincentio returns as duke, Angelo is publicly exposed and forced to confess, and Claudio is revealed to be alive. The play ends with multiple forced marriages and Isabella's ambiguous silence after the duke's marriage proposal.

The main plot from Angelo's rise to the final unmasking.

Vincentio explains to Friar Thomas that he gave Angelo power specifically to test whether authority corrupts virtue.

Isabella asks the nun Francisca about the rules of Saint Clare's order before Lucio arrives with news.

Escalus urges Angelo to show mercy toward Claudio, but Angelo refuses to deviate from the letter of the law.

Constable Elbow drags Pompey and Froth to court, creating comic confusion with his garbled and mangled language.

Vincentio, disguised as a friar, visits Juliet in prison and she describes her grief and joy mixed together.

Lucio cheers Isabella on during her plea to Angelo, watching with satisfaction as Angelo's certainty begins to waver.

Angelo argues to Isabella that showing mercy to Claudio would cause greater harm to society than punishing him.

Vincentio uses his ducal signet ring to convince the prison provost to delay Claudio's execution and join his scheme.

Pompey is arrested by Constable Elbow for carrying lock picks and is hauled back to the prison.

Pompey agrees to become the executioner Abhorson's assistant in exchange for avoiding his own punishment.

Vincentio finds Barnardine too drunk and unrepentant to execute, then learns that prisoner Ragozine has died of fever.

Angelo and Escalus receive Vincentio's letters summoning them to a public hearing at the city gates.

Mariana steps forward at the trial and claims she, not Isabella, was the woman who slept with Angelo.

Vincentio commands Angelo to marry Mariana immediately so she will not be dishonored before any sentence is passed.

Lucio is ordered to marry the sex worker he impregnated and is condemned for repeatedly slandering the Duke.

While the main plot focuses on Angelo and Isabella, a rich world of secondary events shapes the outcome of the play. Vincentio carefully explains his reasons for the experiment to Friar Thomas, Escalus attempts unsuccessfully to check Angelo's severity, and the brothel world of Pompey and Mistress Overdone illustrates the social harm of Angelo's crackdown. In prison, Vincentio works quietly to protect Claudio, using his ducal authority to buy time and ultimately substituting a dead prisoner's head for Claudio's. The public trial at the city gates unfolds through carefully staged moments, including Mariana's surprise testimony and Vincentio's command that Angelo marry her before sentencing. The play closes with Lucio facing punishment for his hypocrisy, completing the restoration of social order in Vienna.

The supporting schemes, subplots, and characters that drive the story.

Angelo expresses doubt about his fitness to govern even as Vincentio publicly praises his unblemished virtue.

Lucio and his companions casually discuss venereal diseases they have contracted from visiting brothel women.

Pompey laments to Mistress Overdone that Angelo's strict new laws will utterly destroy their brothel business.

Escalus tells the disguised Vincentio that the Duke was a measured man devoted above all to self-knowledge.

Lucio persuades a hesitant Isabella that her persuasive gifts could genuinely move Angelo to spare Claudio's life.

Angelo reflects alone that Isabella's purity and piety have stirred forbidden desire in him as no other woman ever has.

Isabella challenges Angelo to search his own heart honestly for the same sinful guilt that condemned her brother.

Angelo warns Isabella that his unimpeachable reputation will make any public accusation against him impossible to believe.

Vincentio persuades Claudio to accept his death calmly, suggesting Angelo's offer may only be a test of Isabella's virtue.

Claudio panics about the unknowable afterlife and desperately begs Isabella to consider accepting Angelo's proposition.

Isabella furiously denounces her brother for asking her to sacrifice her immortal soul to preserve his earthly life.

Lucio unknowingly slanders the Duke's character to his face, calling him foolish, lecherous, and prone to vice.

Vincentio reappears as Friar Lodowick before Escalus and Angelo during the public trial to confirm the women's testimony.

Angelo immediately confesses all his crimes upon being unmasked and begs Vincentio to sentence him to death.

Isabella kneels beside Mariana and pleads for Angelo's mercy, even though she still believes Angelo killed her brother.

Beneath the plot's surface lies a series of pivotal moments in which characters reveal their true natures or are forced to confront uncomfortable truths. Angelo's veneer of cold virtue cracks the moment Isabella appears before him, and the play carefully traces his descent from self-doubt into coercion. Claudio's philosophical acceptance of death collapses under the weight of uncertainty about the afterlife, and Isabella's fury at her brother reveals the impossible moral bind at the heart of the play. Lucio's casual slander of the duke to his face crystallizes the problem of a ruler who governs in secret. At the trial, Angelo's instant confession and Isabella's unexpected plea for mercy are the play's defining revelations, showing that even the most virtuous and the most corrupt characters are capable of surprising the audience.

The key decisions, moral discoveries, and emotional crises that define the play.