Leonato’s household and friends are celebrating the end of the war as they await the imminent return of Don Pedro, their general, and his forces. Hero rejoices that Claudio, her fiancé, is returning with honors, while Beatrice loses no time pursuing her mockery of Benedict, a young officer for whom she professes a great disliking. Anticipating Claudio’s arrival, Hero is thankful that they will soon be united in marriage. No sooner does the army return than Beatrice and Benedict resume their war of traded insults and criticisms, acknowledging the pleasure they find in annoying each other, and imploring God to spare each of them the tiresomeness of the opposite sex. As the company prepares to celebrate the marriage of Hero and Claudio, Benedict forcefully reaffirms his intentions to remain a bachelor, much to the consternation of Don Pedro and Claudio. After Benedict leaves, Don Pedro and Claudio agree that Beatrice and Benedict would be a fitting match for each other, and Don Pedro is certain that with some help, such an unlikely marriage could be achieved. They leave as Somarone and his musicians arrive to rehearse a pompous hymn that he has written for the evening’s festivities. Displeased with the poor performance the musicians accord his masterwork, Somarone is mollified by Don Pedro’s willingness to hire whatever additional forces are needed to assure a proper performance of the piece later that evening. Aware that Benedict is within earshot, Don Pedro, Claudio, and Leonato then begin to discuss all manner of evidence pointing to a supposed change of heart on the part of Beatrice, who is now, they assure each other, passionately in love with Benedict, but unwilling to tell him of her love for fear that he will only continue to mock her. Benedict is stunned by what he hears, and when the others depart, he acknowledges that he, in truth, loves Beatrice as well. He leaves as Hero and Ursula approach. The two women reflect upon the serenity of the night and Hero’s approaching marriage.

Somarone and his musicians have already begun drinking with members of the governor’s house­hold in celebration of the upcoming marriage. As their part in Don Pedro’s plan, Hero and Ursula stage a conversation for the benefit of Beatrice, during which she overhears them discussing a supposed change of heart on the part of Benedict, who, they claim, is dying of love for her. Beatrice is caught in a whirl of conflicting emotions regarding Benedict. She recalls the sadness she felt when he left with the army, and the sorrow and fear that plagued her as she dreamt that he was dying in the battle against the Moors. Finally admitting her affection for Benedict to herself, Beatrice acknowledges that she has fallen victim to love. Hero and Ursula find Beatrice distraught. Much to Beatrice’s distress, they continue to play their parts in Don Pedro’s charade with further assurances of the supposed change that has come over Benedict. The three women give voice to their varied and contrasting thoughts. Hero wishes that her cousin could know the happiness she has found, Beatrice rails against the slavery of marriage, and Ursula acknowledges that even the surest of marriages must face many trials. At the sound of voices calling the couple to prepare for the ceremony, Hero and Ursula depart, and Beatrice soon finds herself in the company of Benedict. Confused, she blurts out her feelings for him, and Benedict assures Beatrice of his love for her. Their encounter is interrupted by the arrival of the wedding party. After Claudio and Hero sign their contract, Leonato announces that there is a second contract, and asks who the second couple might be. Benedict seizes the opportunity and confronts Beatrice, but spurred by stubbornness, each continues to deny loving the other as any­thing more than a friend. When written evidence to the contrary is produced, they finally agree to marry, while offering face-saving rationalizations: Benedict marries her out of compassion, Beatrice marries him so he will not die of consumption. They affirm that love is an unpredictable fire, and, caught in its flame, they call a truce to their battles, at least until tomorrow.