Leonato and Antonio are talking before Leonato's house. Antonio tries to console his brother, who is presently very depressed. Leonato believes that Hero is innocent and he is furious at anyone who would dare accuse her of being nothing less than a prostitute. Don Pedro and Claudio enter, much to the brothers' rage, and they are quick to inform the princes that Hero is dead. Don Pedro and Claudio quickly retreat, as Leonato has worked himself up into a rage.
Benedick enters and Don Pedro and Claudio complain about how they were harassed by Leonato and Antonio. They do not know, however, that Benedick also believes Hero to be innocent. Benedick challenges Claudio and Don Pedro to a duel. He accuses Claudio of killing Hero with his malicious insults. Don Pedro and Claudio, surprised at their friend's anger, are taken aback. They inform him of Beatrice's love, which only serves to further enrage him. Benedick leaves the princes after informing them of Don John's escape from Messina.
Don Pedro and Claudio are left alone and are very surprised at what has happened. Benedick has declared his love for Beatrice, but he believes Hero to be innocent. Suddenly, Dogberry and Verges enter with the prisoners Conrade and Borachio. Borachio confesses the whole crime to Don Pedro. Claudio immediately repents his harsh words and mourns sweet Hero's death.
Leonato and Antonio enter and also hear the confession from the prisoners. Claudio begs Leonato for mercy. Leonato tells Claudio that nothing can bring Hero back, but to atone for his sins Claudio can create an epitaph for her grave and sing at her funeral that night. Also, Leonato tells Claudio that he should marry Hero's cousin the next day. Claudio agrees to do everything in Hero's memory. Leonato leaves with the watchmen to question Margaret and her role in the scandal.