Grandfather is becoming sicker and sicker with cholera as he and Mattie walk to the Ludingtons. He finally becomes so sick and feverish that he has to stop. He sends Mattie to a nearby farmhouse to buy food and a few blankets. The two have hardly eaten anything for two days.
Mattie doesn't want to leave Grandfather alone in his sick state, but he assures her that he will be fine. However, when she arrives, Mattie finds the farmhouse locked up. A person inside tells her to go away: clearly the farm residents fear contracting cholera.
Mattie feels the world is turning upside when the farm folk won't help her. However, she finds pears and gathers them up, then heads for a chestnut tree. As she does so, she begins to feel very sick and lightheaded and loses consciousness.
The scene shows Mattie having to take responsibility for herself and her grandfather as he gets sick. The cholera epidemic forces her to use her wits and resourcefulness to survive, such as by gathering the pears when she cannot buy food from the farmhouse.
The scene also shows the kind of fear the deadly epidemic caused in people. Ironically, the residents of the farmhouse were right not to let Mattie in, as she was infected with the disease and would have spread it.