Act Three, Scene One
Hero tells her servant Margaret to fetch Beatrice and tells her that she overheard Hero and Ursula gossiping about Beatrice in the orchard. Hero then orders Ursula to talk about Benedick as if he were madly in love with Beatrice. She agrees, and they wait until they see Beatrice hide herself in the orchard before walking towards the hiding spot.
They arrive where Beatrice is hiding and Hero informs Ursula that Benedick is madly in love with Beatrice, but that she will never tell Beatrice because she is afraid her cousin would only ridicule Benedick. Ursula agrees, and Hero then mentions that Beatrice is so sharp tongued that she often finds faults in men that are not really there. Ursula then praises Benedick as a man, saying he is one of the best men in Italy and would be an excellent match for Beatrice. After they leave, Beatrice steps forward and comments that rather then be condemned for her pride and scorn she will requite Benedick's love and marry him.
Act Three, Scene Two
Claudio, Don Pedro and Leonato find Benedick to be acting sadder than usual, and make fun of him as if he is in love. He does not deny their charge, but finally asks Leonato if he could have a word with him in private. Don Pedro tells Claudio that Benedick must want to discuss Beatrice with Leonato.
Don John arrives and informs Claudio and Don Pedro that Hero is unfaithful. He offers to prove it to them, telling them to go with him that night and look into Hero's chamber window. Claudio states that if he sees any reason not to wed Hero that night, he will shame her in the church before the wedding ceremony the next day. Don Pedro supports him and they promise to meet Don John that night.
Act Three, Scene Three
Dogberry and Verges, both fools in charge of the watchmen, get one of their men and make him the constable of the watch for the night. He agrees, but asks what he should do if he orders a man to stop and the man refuses. Dogberry tells him to ignore the man, and good riddance of a knave, because they can only stop loyal subjects of the Prince. Verges then orders the man to keep silence throughout the town. They leave the man to his job as constable, and Dogberry orders him to wake him up only if something important comes up.
Borachio and Conrad arrive and accidentally stand within hearing distance of the watchman whom Dogberry appointed constable. Borachio tells Conrad that he earned a thousand ducats from Don John that night because he wooed Margaret in Hero's room and called her Hero. Meanwhile, Don John had brought Don Pedro and Claudio to orchard where they watched this whole scene and became convinced that Hero was committing infidelity.
One of the night watchmen, having overheard this story, arrests Borachio and Conrad for villainy. They agree to go peacefully and are taken to be judicially interrogated.
Act Three, Scene Four
Hero is getting dressed by Margaret for her wedding that day. She sends Ursula to fetch Beatrice, who arrives but has lost her wittiness and has also caught a cold. Margaret makes severally sexually explicit puns before mentioning to Beatrice that Benedick is now in love. Margaret then implies that perhaps Beatrice will someday decide to fall in love much the Benedick has. Ursula interrupts her and informs Hero that the men are all gathered to take her to the church.
Act Three, Scene Five
Dogberry has gone to Leonato to inform him that two suspicious men were arrested the night before. He asks Leonato to examine the men, but since the wedding is that day, Leonato refuses and orders Dogberry to conduct the examination himself. Dogberry orders Verges to bring one of his men who knows how to write so that they can write down the entire examination and bring it to Leonato.
The issue of noting, or making much ado about nothing, comes up when Claudio and Don Pedro, led by Don John, look at window and think they see Hero. They fail to note that it is not Hero, but instead Margaret. This is fabrication through substitution, and it leads Don John to stand condemned at the end of the play.
This scene also plays on men's fears of female infidelity. Claudio tells us, "If I see anything tonight why I should not marry her, tomorrow in the congregation where I should wed, there will I shame her" (3.2.103-107). This fear is so strong that Benedick declared himself a bachelor as a result, he is terrified of wearing bull's horns, a sign of the cuckold.
Gardens are again dangerous places to be. Hero and Ursula are talking in the orchard. This is not merely a plot against Beatrice, but also against female virginity. In fact, gardens can be seen as representing the female sexuality, and they are dangerous places because they are where virginity is compromised. This can be seen when Claudio convinces Don Pedro to win him Hero's heart, a scene that takes place in a garden. In this act, Beatrice will be tricked into loving Benedick by what she overhears in an orchard. Indeed, Hero's reputation, and also Claudio's perception of her virginity, is lost when Claudio and Don Pedro stand in the orchard and watch Borachio woo Margaret.
The only way to clear up the confusion inherent in the play is to write everything down. Writing becomes a way of clarifying and clearing up the mistakes. Dogberry says, "get the learned writer to set down our excommunication [a joke, he means examination]" (3.5.55-56). This is the first point in the play where writing appears. It will later be used by Benedick and Beatrice, the Sexton, and Claudio who will write the epitaph to Hero.