When Jem reported to Cal that ol' Tim Johnson was wobbling suspiciously down the street, Calpurnia came out to see for herself. She recognized immediately that the dog had rabies and quickly alerted the neighborhood. First she called Atticus and then she told the town operator, Eula May, to notify "Miss Rachel and Miss Stephanie Crawford and whoever's got a phone on this street" that "a mad dog's comin'." She then ran to the Radley's house to give them the news since they had no phone. She "banged on the door" and yelled for the Radleys, but she received no response. The significance of this was simple: Nathan Radley was probably not at home, and Boo never came outside. The madness outside displayed by Tim Johnson was dealt with in a different manner by the Radleys, whose madness was contained within the four walls of the home.