Leonato, Hero’s father, falls into a state of deep grief and shock. Torn by his worries about whether Hero is indeed chaste as she claims and his questions about what actually occurred, he cannot function. His brother Antonio tries to cheer him, telling him to have patience. But Leonato answers that although people can easily give advice when they are themselves not unhappy, people in great pain cannot follow the advice so easily. Don Pedro and Claudio enter, see Leonato and Antonio, and quickly try to leave. But Leonato follows them and accuses Claudio of having lied about Hero and having caused her death. Leonato announces that, despite his great age, he challenges Claudio to a duel for the crime Claudio has committed against Hero by ruining her good name; Leonato states that he is not too old to kill or die for honor and for the love of his child. The embarrassed Claudio and Don Pedro pretend to ignore their challengers. Finally, Leonato and Antonio leave, vowing that they will have their revenge.
After Leonato and Antonio depart, Benedick enters. Claudio and Don Pedro welcome him, asking Benedick to employ his famous wit to cheer them up. But Benedick is in no mood to be funny. He tells Claudio that he believes Claudio has slandered Hero, and he quietly challenges him to a duel. When the other two keep on trying to joke with him, Benedick finally discloses that he can no longer be their companion since their slanderous accusations have murdered an innocent woman. Benedick informs Don Pedro that Don John has fled the city and leaves. At first, Claudio and Don Pedro take in this change in Benedick’s behavior and the information of Don John’s flight with shock and confusion. Slowly they begin to realize Benedick’s serious intent—and they rightly guess that his love for Beatrice must be the only thing that could have motivated him to challenge his dearest friend to a fight to the death.
Dogberry and Verges suddenly enter, accompanied by the other men of the Watch, dragging behind them the captured villains Conrad and Borachio. Dogberry tells Claudio and Don Pedro that Borachio has confessed to treachery and lying, and Borachio admits his crime again. Shocked and horrified, Claudio and Don Pedro realize that this information supports Hero’s true innocence and that she has died (so they think) because they have wrongly accused her, tarnished her reputation forever, and ruined her family.
Leonato and Antonio return. Claudio and Don Pedro beg Leonato’s forgiveness, offering themselves up to any punishment Leonato thinks fit for killing his daughter with wrongful accusations. Leonato orders Claudio to clear Hero’s name by telling the entire city that she was innocent and to write her an epitaph—that is, a poem honoring her in death—and to read and sing it at her tomb. He also tells Claudio that Antonio has a daughter who is very much like Hero, and he asks Claudio to marry his niece in Hero’s place in order to make up for the lost Hero. Claudio, weeping at Leonato’s generosity, accepts these terms. Leonato orders that Borachio be carted away for further interrogation.
