He instigates the second plot against Claudio. He meets with Margaret in Hero’s chambers, causing Claudio to think he is seeing Hero and Borachio together and that Hero is therefore being unfaithful to him. He is later arrested by Dogberry’s watchmen and forced to reveal what actually happened .
And there shall appear such seeming truth of Hero’s disloyalty
I whipt me behind the arras; and there heard it agreed upon that the prince should woo Hero for himself, and having obtained her, give her to Count Claudio.