So the villain tries something else, this time successfully. He has an underling set up a scene one night in which Hero's maid is mistaken for her, in illicit romantic company on her balcony. They are seen by Claudio and other witnesses. The prospective bridegroom is understandably distraught — and furious. His vengeance is to humiliate her at their wedding the next day, confronting her with the supposed crime in front of everyone.
Meanwhile, Benedick and Beatrice — remember Benedick and Beatrice? — are more shaken than most by the scandal, though neither believes Hero capable of such behavior. Beatrice tells him there's only one thing that can secure her love: "Kill Claudio!" (My favorite moment in the production is the ironic instant she hisses this instruction: at their first embrace.)
So will Benedick duel his best friend to the death? Will the honor of Hero be recovered and all else be well? Oh, you know Shakespeare won't let you down. But to be sure, better see for yourself.