By Chapter 10 of Harper Lee's To Kill a Mockingbird, Scout and Jem are starting to feel disgruntled by their father's persistent absence due to his devoted work on the Tom Robinson case. Scout also blames Atticus's absence on old age, saying, "Atticus was feeble: he was nearly fifty" (Ch. 10). As a result of Atticus's increased absence, the Finches' cook Calpurnia, Cal for short, spends even more time taking over as a surrogate parent. One way in which she acts as a surrogate parent in Chapter 10 is by protecting the children from a rabid dog.
One Saturday, Scout and Jem went hunting with their air-rifles in search of a rabbit or squirrel to shoot at when Jem noticed a dog named "old Tim Johnson," who belonged to Mr. Harry Johnson, driver of the "Mobile bus," coming down the street. Whatever way the dog was behaving worried Jem enough to decide they should go home and inform Cal. When they do, though Cal protests at being asked to come out and look at a dog, she finally does, and they all observe that the dog "walked erratically, as if his right legs were shorter than his left legs." Calpurnia then ran the children inside the home, "shut the wood door behind [them]," and phoned Mr. Finch, who tells her to warn everyone on the street that a "mad dog's comin'," meaning a rabid dog. Soon Atticus arrives with Sheriff Heck Tate, who has a riffle but insists Atticus shoot the dog with the rifle because Heck knows he's not nearly as good a shooter as Atticus.