In the prison, the duke, disguised as a friar, attempts to comfort Claudio and prepare him for his death with assurances of the ephemerality of life. The duke exits when Isabella arrives on the scene to tell Claudio of Angelo's treachery and her inability to save him. When he begs her to meet Angelo's demands, Isabella upbraids him and leaves in anger.
The duke, having eavesdropped on their conversation, returns to tell the prisoner that Angelo's offer was no more than a test: The execution is inevitable. The duke then goes apart with Isabella to suggest a plan that he declares will save Claudio and be of some help to Mariana. The latter, betrothed to Angelo, was deserted by him when her dowry was lost in a shipwreck. Mariana, if she consents, will be a substitute for Isabella in meeting Angelo's demands. Isabella agrees to the plan.
The duke finds Pompey being led off to prison by the constable, Elbow. Ascertaining that he is a bawd, the duke in his friar's guise lectures Pompey. When Lucio arrives on the scene, Pompey appeals to him to take his part, but that gentleman merely condemns him further, refusing even to go bail for him. Elbow leads Pompey away, and Lucio launches into an attack on the duke's own virtue. The duke challenges him to repeat his remarks to the duke's face when he has returned. Lucio leaves, uttering still more damning remarks. Escalus now comes on the scene with Mistress Overdone in custody. Convinced that Lucio has informed against her, she charges him with getting a bawd with child and failing on his promise to marry her. In discussion with Escalus after she has departed, the duke claims to be a friar of another country, come to Vienna on special church business. He questions Escalus about the duke and hears his praises. Having discussed Claudio's state of mind on the eve of his execution, Escalus exits and the duke delivers a soliloquy on the subject of false virtue.
In Scene 1, the duke makes his disguise believable by acting the role he has adopted. As a friar, he makes a lengthy speech (6-41) reminding Claudio of life's little worth. Claudio is comforted and ready to accept his fate when his sister arrives.
The duke having retired, Isabella informs Claudio that she is unable to stop his execution. She hints that there is a way but one that is impossible to take. Grasping at straws, Claudio questions her. Isabella's explanation is slow and tantalizing, creating a buildup of suspense until she at last reveals Angelo's demands. Claudio's initial response is firm: "Thou shalt not do't" (103). But the desperation he was brought to by Isabella's slow rendering of her tale begins to take effect, and he slips a bit. Perhaps it would not be a deadly sin. Angelo would surely know. Driven by a fear of death that he describes eloquently in a speech reminiscent from Hamlet, he at last begs her to yield to Angelo.
Isabella's response at this point in Scene 1 is a show of violent temper, sparing Claudio no accusation. When earlier in the same scene he had shown his readiness to accept his execution, she had proclaimed proudly, "There spake my brother; there my father's grave / Did utter forth a voice" (86-87). Now she turns the praise to accusation: "Heaven shield my mother play'd my father fair! / For such a warped slip of wilderness / Ne'er issued from his blood" (141-43). Isabella's critics point to this speech as showing a lack of understanding and compassion. Her defenders, however, point out that Isabella's anger is a defense against her own temptation to yield to a beloved brother's pleas. The outburst both reflects the strained condition of her nerves and awakens Claudio from his self-pity. The reader should remember too that to Isabella, her brother is asking her to sell her soul, and his too, in exchange for "six or seven winters" (76) added to his life.
The duke returns to bring Claudio back to his earlier acceptance of the inevitability of his doom. Claudio repents: "Let me ask my sister pardon. I am so out of love with life that I will sue to be rid of it" (174-75). He recognizes the rightness of Isabella's decision. Isabella's critics suggest that she should have replied to Claudio's anguished words, but she has gone aside, perhaps out of hearing. Much has been made of the fact that she does not speak to him when he is revealed to be alive in the final scene. However, an impassioned embrace might tell all. Certainly here is an example of the extent to which the play is subject to divergent interpretations. A director might portray Isabella as cold and heartless or as a devoted sister simply by varying her actions in the two scenes.
When the duke now takes Isabella aside, his warm praise of her goodness to some extent foreshadows his proposal of marriage in the final scene.
The duke expresses surprise at Angelo's treachery (189-90) but a few lines later makes it plain that he is well aware of the man's questionable treatment of his betrothed (233-39). This conflict is an example of the inconsistencies in the play.
In answer to the duke's suggestion that there may yet be a way to save Claudio, Isabella declares her willingness to do anything that is not foul.
The bed trick upon which the plot turns is presented in Scene 1. Mariana is characterized as "a poor gentlewoman" (227), whom Isabella recalls having heard of: "good words went with her name" (219-20). The duke stresses the good that will come of the substitution: "the doubleness of the benefit defends the deceit from reproof" (266-68). Isabella will not only save her brother and her own honor but may also do some good for Mariana.
The reader may wonder why the duke does not solve the dilemma by simply reassuming his control of the government. However, in doing so, he would end the play and its potential as a vehicle for a dramatic contrasting of strict law with mercy.
In Scene 2, the minor characters of the play share a fate parallel to Claudio's. Perhaps more vulgar, but certainly no less human than that gentleman, they are deprived of their livelihood and imprisoned by the severe application of the law.
The duke plays his friar's role again by lecturing Pompey on his vices, discoursing on the sins of the world and telling Escalus of his progress in dealing with the condemned Claudio's fears. The disguise proves profitable to him. He is able to see how the laws are being enforced in his absence with the arrests of Pompey and Mistress Overdone. Furthermore, he can judge the loyalties of his subjects. Lucio gives himself away for an irreverent gossip in his bawdy accusations against the duke. He insists that he would hold to his wards in the presence of the duke. Ironically, the duke himself is his audience. Questioning Escalus, the duke receives a good report of himself and one that proves its speaker's honesty, loyalty, and good sense. Escalus' words can be taken as a further characterization of the duke since he is one of his closest advisors. The duke, he says, is a man who "above all other strifes, contended especially to know himself" (246-47), and who took his joy from the happiness of others. The duke, then, is an analytical man who attempts to know himself completely. He is, perhaps, just the sort of man who would disguise himself in order to check the seeming virtue of Angelo. Lucio's estimation of the duke carries no weight since he does not have the acquaintance with him that he claims and, in fact, as is clear in this scene, enjoys a good joke at another's expense.
Lucio refers twice in Scene 2 to a common theme: the universality of the crime for which Claudio is condemned. The vice, he says, "is of a great kindred, it is well allied: but it is impossible to extirp it quite, friar, till eating and drinking be put down" (108-11). Angelo's strict enforcement of the law will, according to Lucio, "unpeople the province with continency" (184-85).
Lucio enjoys some amusement at Angelo's expense, claiming that a man so cold and so harsh against sexual crimes could not have been conceived and born in the usual fashion. His remarks to Pompey tend to condemn him rather than aid him, as Pompey had hoped. Lucio is revealed to be a man who enjoys a few witty remarks at the expense of a friend before he lifts a finger to assist him. He has even informed against Mistress Overdone. She, however, retaliates by providing the duke with the information that he will use against Lucio in the final scene. He has gotten a whore with child and failed to keep his promise of marriage. While enjoying the plight of those around him, he is headed toward his own downfall. He is amusing but certainly no friend. Only his actions on Claudio's behalf speak in his favor.
In his last words to Escalus in Scene 2, the duke foreshadows events to come when he comments on Angelo's severity: "If his own life answer the straitness of his proceeding, it shall become him well; wherein if he chance to fail, he hath sentenced himself" (269-71). This obvious reference to Angelo's assault upon Isabella is topped off with an entirely unnecessary soliloquy of rhymed couplets on the subject of false virtue. It is commonly speculated that this rather trite speech, jarringly out of step with the rest of the scene, was appended to it by some hand other than Shakespeare's.
The duke promises that "disguise shall, by the disguised, / Pay with falsehood false exacting" (294-95). In other words, the duke will punish Angelo's deceit with deceit of his own. The deputy's lust, disguised by counterfeit virtue, and his false promise to save Claudio's life are paid back with the duke's own tricks: the substitute bed partner and Ragozine's head for Claudio's. Angelo gets measure for measure.