Act IV Scene 1 Summary:
The Duke finds Mariana, and exchanges a few cursory words with her. Isabella enters as Mariana leaves, to tell the Duke that she has agreed to Angelo's plan, and describes the place of meeting. Isabella said that she told Angelo she could only stay briefly, and that she would be bringing a servant with her, which means she can bring Mariana without suspicion. Isabella has a word with Mariana, and Mariana agrees to go with the plan, provided the "friar" agrees, which he does. The Duke still has to assure her that she is doing no sin, because she is only fulfilling the contract she had with Angelo some time ago.
Isabella's description of the place where she is to meet Angelo shows that she is resigned to this plan that the Duke has made, and that the significance of this exchange is completely clear to her. She tells of the place she is to meet Angelo: "he has a garden circummured with brick, whose western side is with a vineyard backed". The images are heavy with darkness and concealment, of concern to Isabella since they will hide this plan and her visit from others. She speaks with sadness almost about the "heavy middle of the night," as if she actually had to sleep with Angelo; her pride has obviously been wounded by agreeing to this exchange, even if she does not have to act upon it.
The Duke's words also betray feelings of solemnity about this plan; his description of "millions of false eyes" convey his nervousness at this risky plan, and that if it does not work and is exposed, it will certainly cause him grief. He wishes there were some other way, as he knows that this plan will have heavy consequences, and if it backfires, his reputation and Claudio's life, among other things, will be at risk. When he reassures Mariana about the plan not being sinful, it seems that he is convincing himself as well; the Duke is a conscientious man, and could not in good faith trick a woman into committing an unpalatable act even if that meant saving a life.
Act IV Scene 2 Summary:
The Provost asks Pompey whether he could cut off a man's head, and of course Pompey, being a clown, answers humorously. The Provost needs an assistant for the executioner since both Barnardine and Claudio are to die the next day; if Pompey agrees to do the service, the Provost says that Pompey's crimes will be forgiven. Pompey agrees, and is introduced to Abhorson, the resident executioner. Abhorson doesn't want to take him as an assistant since Pompey is a bawd, but has little choice. A comic scene follows, as all scenes involving Pompey the clown must turn comic somehow.
The Provost goes to Claudio, showing him the warrant for his death. Claudio's cellmate, Barnardine, who is also to be executed, is lazy and sleeping, Claudio tells him. The Duke enters, still dressed as a friar, and says there is some hope for Claudio yet. A message comes from Angelo, and the Duke is convinced that it is a pardon; but it is an order to go ahead with Claudio's execution, despite whatever orders to the contrary from other sources. All is not resolved as Angelo promised or as the Duke hoped; they will still have to struggle to get Claudio freed and pardoned. The Duke asks the Provost to help him with Angelo; he wants the Provost to send Angelo the head of Barnardine, and say it is Claudio's, so that the Duke can have a few more days to try and save Claudio. The Provost is unwilling to deceive Angelo so plainly, but the Duke conveniently produces a letter from the absent Duke, and tells the Provost that his help will secure justice for Claudio.
The Duke's defense of Angelo might seem out of place since the Duke already knows otherwise of Angelo, but it shows that the Duke is not yet prepared to expose Angelo and his sins. It is ironic that the Duke would declare, in the guise of an honest friar, that Angelo is "just," when he and others know this to be falsehood.
Just as the Duke was incorrect in his initial appraisal of Angelo's ability to rule, here he is similarly wrong in his belief that "when vice makes mercy, mercy's so extended". The Duke tends to appraise Angelo's character too kindly, and believe that Angelo actually knows mercy, which he has not shown to this point. However, the Duke is clearly a very canny character; he has no intention of giving in while Angelo has not delivered on his promise, and wants to teach Angelo something about mercy, a theme running through the entire play.
Again, the Duke uses his canny logic and persuasive skills to gain complicity for his plots. He is able to extract mercy from the Provost, though Angelo unfortunately cannot be similarly moved. Also, he uses the Provost's loyalty to the Duke to justify this deception. Hopefully, the Duke's well-intentioned plans will come to good use, and not backfire on him.
Act IV Scene 3 Summary:
Pompey the clown enters, to provide a bit of running commentary on things in the prison. He finds that many that used to frequent Mistress Overdone's brothel are locked up in jail, so he almost feels at home with all the people of poor morals and such. Barnardine is called forward to be executed, and tries to shrug the officers off by saying that he is tired. Abhorson and Pompey fetch him out, and the Duke tries to counsel him. Barnardine insists he will not die that day, since he is too tired and too drunk to want to. The Duke says that to execute Barnardine then, with his soul completely unprepared, would be a terrible thing; luckily, a man in the prison died the night before, so they can use his head to send to Angelo rather than Barnardine's.
Isabella comes to the jail, to see if her brother's pardon came through as it was supposed to. The Duke tells her that her brother was executed, so that she will be happier when she finds out the truth later. Now, he is willfully keeping her in ignorance, a move that will keep him in control of the game, but seems more self-serving than beneficial.
The Duke tells Isabella not to be sad, since the Duke will be back tomorrow, to take power back from Angelo; he says that the Duke will make things right and ensure that justice happens, and Isabella says she will try to suppress her grief. Lucio enters, and expresses his condolences; he says that if the Duke were presiding over Claudio's case, Claudio certainly would have been allowed to live. Lucio then offers to tell more about the Duke, and offers up that he once got away with getting a woman pregnant when the Duke was there. They exit together.
Again, the Duke is forced to do even more improvisation, as plans go awry; but, fate is obviously on his side, since the man who died looks like Claudio, so his head given to Angelo will seem more convincing. The Duke here seems like he means to be the manipulator of the action, and is doing things with a plain purpose in mind; the fact that he decides to tell Isabella that her brother is dead, so that she can be happier later, serves no purposes but the Duke's hidden ones. Rather than trying to make things right, here he is deciding what outcome he wants, and is manipulating what people find out in order to produce these results. Through these self-serving machinations, the Duke appears less benevolent, and more like a control addict.
The Duke tells Isabella "trust not my holy order if I pervert your course"; this is meant to comfort Isabella, but represents a big license on the Duke's part. Throughout the play, he has used his disguise as a friar to gain people's trust and complicity in his plans; here, he plays on Isabella's trust in the clergy to get her to go along with his plan. It is all well and good that the Duke is doing most of this for the benefit of Claudio, but he is assuming liberties and roles that are not his and that he knows nothing of. It seems almost like an abuse of the priesthood for a man in a friar's disguise to be allowed to assume the duties, status, and respect that go along with the office merely for wearing the clothes. The Duke, in his pretending to be an actual friar and assuming all the rights and responsibilities that go along with it, might be going too far in his do-gooding.
Lucio's confession that he once denied getting a woman pregnant means that he probably does not know he is talking to the Dukeotherwise, why would he risk being caught and tried for the same offense again? It is about time that the Duke revealed himself, and abandoned the many privileges he has enjoyed by being disguised.
Act IV Scene 4 Summary:
Escalus and Angelo receive notice of the Duke's return; they also note how each letter the Duke has sent them has contradicted any other, which makes them fear that he is somehow mad. Angelo thinks it would be a good idea to announce that any who have grievances can meet at the place where they are to receive the Duke back into the city; Angelo thinks this will protect him from any legal actions, in case there are any issues that have not yet been dealt with.
However, Angelo also knows that this might give Isabella a forum in which to tell of Angelo's wickedness and her deal with him. He believes that she will not accuse him, because she would be shamed by saying that Angelo took her virginity. Angelo also says that he should have let Claudio live, since his offense was not that bad after all, but that sometimes he has to do what he would rather not do.
Escalus and Angelo's suspicion about the Duke's ruse shows that the Duke's time is running short; from his notes, they can already see that either he is not being honest, or he is being flagrantly contradictory in his letters. Angelo's use of the Duke's entrance to have an airing of grievances shows that he is very canny; he would not take responsibility himself for things he can easily weasel out of.
Angelo is finally realizing what the potential consequences of his deeds might be; at last, he is showing remorse. He also sees the irony of his situation, that he is supposed to enforce the law, yet it was he who broke it with his treatment of Isabella. But, he still believes in the power of his reputation to shield him from accusation, another theme of the play. Angelo is overconfident, however; he may think that he is too highly regarded to be exposed, but he is also widely disliked, which works against him.
Angelo repents here of giving Claudio a death sentence, showing that he is not merciful in deed, but that he does have better judgment than he has shown throughout the play. Angelo excuses himself, however, by saying that having power means that he has to do things that he would rather not do. He has still not learned how to govern with moderation, even if he is closer to understanding the need for mercy in a ruler.
Act IV Scene 5 Summary:
The Duke is telling Friar Peter to keep the letters he is giving him, and to follow the plans that the Duke has laid out; the Duke also says that the Provost will play along, and knows what he is to do as well. He has the Friar call a few men of the city together for his return, and then continues his preparations.
Here, we get a glimpse of the Duke as a kind of director of the play; he tells people what parts to do and how, has orchestrated a complicated set-up to achieve the end results that he desires. The theme of manipulation comes to the fore, as we begin to realize how much of the action of the play has been driven or made by the Duke. The Duke, although he seems benevolent and fair when compared with Angelo, is actually not quite as good as he seems; he is secretive, conniving, and manipulates people shamelessly, even if it is toward good ends.
Act IV Scene 6 Summary:
Isabella and Mariana are getting ready to play their part in the Duke's plan. Isabella has to accuse Angelo with Mariana by her, though she would rather not be so bold; she also says that the Duke warned her that he might not take her side at the beginning, which worries her. Friar Peter enters, and bids them come to the gates since the Duke is about to come in. Many citizens are gathered, and it is time to play their parts in this thing that the Duke has constructed for them.
"'Tis a physic that's bitter to sweet end": this seems to be the Duke's philosophy regarding how he is handling this entire situation, and also it tells of the overall course of the play. So far, this play has not been a comedy; many of the characters, like Claudio and Isabella, have been put in very trying situations, and subjected to a great deal of unfairness. People have died, nearly escaped execution, and had to evade blackmail; yet, the play will work its way to a supposedly neat, happy ending, as is the convention of Elizabethan comedies.