In “Much Ado About Nothing,” the watchman who discovers the plot against Hero is Dogberry.
Dogberry is the chief constable of Messina and leads the local watch, a group of citizen-watchmen responsible for keeping order. He is self-important, incompetent and famous for malapropisms: he repeatedly uses grand or official-sounding words incorrectly. His comic ineptitude makes him seem unlikely to solve anything, yet his watch accidentally uncovers the central deception.
During the night watch, the men overhear Borachio boasting to Conrade about Don John’s scheme to make Claudio believe that Hero has been unfaithful. They arrest the pair and bring them into Dogberry’s jurisdiction. Although Dogberry’s confused explanations initially frustrate Leonato, the prisoners’ confession eventually exposes the plot and proves Hero’s innocence.
Verges is Dogberry’s partner, while Borachio and Conrade are the conspirators overheard by the watch. Dogberry is therefore the accepted answer even though the watchmen collectively hear the incriminating conversation. His accidental success helps restore order before the play’s final reconciliations.