CLAUDIO: O, my lord,
When you went onward on this ended action
I looked upon her with a soldier's eye,
That liked, but had a rougher task in hand
Than to drive liking to the name of love.
But now I am returned and that war thoughts
Have left their places vacant, in their rooms
Come thronging soft and delicate desires,
All prompting me how fair young Hero is,
Saying I liked her ere I went to wars.
As lightly as Claudio falls in love, he falls out: He is easily convinced by a scene contrived by Don Pedro's evil brother, Don John the Bastard, which makes Hero seem to be having an affair with another man. Claudio and Hero are dull people who fall in love dully; the stakes are low.
Much more interesting is the relationship between Hero's cousin Beatrice and Claudio's fellow soldier Benedick, who can best be described as "frenemies." Their battle of wits is longstanding:
BEATRICE: I wonder that you will still be talking, Signior Benedick, nobody marks you.
BENEDICK: What, my dear Lady Disdain! Are you yet living?
BEATRICE: Is it possible disdain should die while she hath such meet food to feed it as Signior Benedick? Courtesy itself must convert to disdain if you come into her presence.
But Beatrice and Benedick too--though they both declaim constantly against marriage--fall in love easily, when their friends contrive that they "overhear" accounts of how dearly each loves the other. This is sensible, not only because they clearly have a great affinity for each other behind their verbal sparring, but because Shakespeare subtly suggests that Benedick once jilted Beatrice. Still, if it were not for the machinations of Don John, love in this play would have very little to challenge it.
Don John's machination leads Claudio to cruelly denounce Hero on their wedding day, and then to one more contrivance: Hero and Leonato pretend that the grief has killed her, that Claudio might realize how much he truly loved her. Were it not for Beatrice, this might be a bland bit of Shakespearean silliness, but it casts a pall over her newly open love for Benedick:
BEATRICE: You have stayed me in a happy hour. I was about to protest I loved you.
BENEDICK: And do it with all thy heart.
BEATRICE: I love you with so much of my heart that none is left to protest.
BENEDICK: Come, bid me do anything for thee.
BEATRICE: Kill Claudio.
Benedick is little deeper than his wit, but Hero's "death" allows Beatrice to exhibit a latent fury we would not have expected, and duel with Claudio becomes a condition of her marriage with Benedick. For a moment, she seems horribly like a young Lady Macbeth:
O, that I were a man! What, bear her in hand until they come to take hands, and then, with public accusation, uncovered slander, unmitigated rancor--O God, that I were a man! I would eat his heart in the marketplace.
This is as close as Much Ado About Nothing comes to losing its lightheartedness; Hero's ruse is exposed before the challenge can materialize. I admit that this is one of my chief disappointments with the play (the other being the weak comedy of the chief of the Watch, Dogberry, who is always using words incorrectly--ha!), that we are not permitted to witness the result of this challenge. That would have been a different play entirely, one in which love is far from nothing, but a powerful force of questionable value. As it is, the play ends with a double marriage and all forgiven, except for Don John, who disappears as neatly as all evil must in comedy, and the first recorded instance of this rom-com cliche:
BENEDICK: A miracle! Here's our own hands against our hearts. Come, I will have thee, but by this light I take thee for pity.
BEATRICE: I would not deny you, but by this good day, I yield upon great persuasion, and partly to save your life, for I was told you were in a consumption.
BENEDICK: Peace! I will stop your mouth.