Detective Comics (1937-) #503
As the electoral campaign starts in Gotham City, Batman goes out on patrol and is shot with a dart. He takes the sample to the Batcave to analyze it, but is unable to find anything wrong. The next day, Bruce realizes that his mere presence causes fright in the people nearby and he deduces there must be a connection between the dart and the strange events. Robin enlists Batgirl's help and they get in touch with Batman, who provides them the instructions necessary to crack the case.