The story is narrated by a young girl named Jean Louise Finch, who is almost always called by her nickname, Scout. Scout starts to explain the circumstances that led to the broken arm that her older brother, Jem, sustained many years earlier; she begins by recounting her family history. The first of her ancestors to come to America was a fur-trader and apothecary named Simon Finch, who fled England to escape religious persecution and established a successful farm on the banks of the Alabama River. The farm, called Finch’s Landing, supported the family for many years. The first Finches to make a living away from the farm were Scout’s father, Atticus Finch, who became a lawyer in the nearby town of Maycomb, and his brother, Jack Finch, who went to medical school in Boston. Their sister, Alexandra Finch, stayed to run the Landing.

A successful lawyer, Atticus makes a solid living in Maycomb, a tired, poor, old town in the grips of the Great Depression. He lives with Jem and Scout on Maycomb’s main residential street. Their cook, an old black woman named Calpurnia, helps to raise the children and keep the house. Atticus’s wife died when Scout was two, so she does not remember her mother well. But Jem, four years older than Scout, has memories of their mother that sometimes make him unhappy.

In the summer of 1933, when Jem is nearly ten and Scout almost six, a peculiar boy named Charles Baker Harris moves in next door. The boy, who calls himself Dill, stays for the summer with his aunt, Miss Rachel Haverford, who owns the house next to the Finches’. Dill doesn’t like to discuss his father’s absence from his life, but he is otherwise a talkative and extremely intelligent boy who quickly becomes the Finch children’s chief playmate. All summer, the three act out various stories that they have read. When they grow bored of this activity, Dill suggests that they attempt to lure Boo Radley, a mysterious neighbor, out of his house.

Arthur “Boo” Radley lives in the run-down Radley Place, and no one has seen him outside it in years. Scout recounts how, as a boy, Boo got in trouble with the law and his father imprisoned him in the house as punishment. He was not heard from until fifteen years later, when he stabbed his father with a pair of scissors. Although people suggested that Boo was crazy, old Mr. Radley refused to have his son committed to an asylum. When the old man died, Boo’s brother, Nathan, came to live in the house with Boo. Nevertheless, Boo continued to stay inside.

Dill is fascinated by Boo and tries to convince the Finch children to help him lure this phantom of Maycomb outside. Eventually, he dares Jem to run over and touch the house. Jem does so, sprinting back hastily; there is no sign of movement at the Radley Place, although Scout thinks that she sees a shutter move slightly, as if someone were peeking out.

The story that constitutes almost the entirety of To Kill a Mockingbird is set in the time between Scout Finch’s fifth and ninth birthdays, but Scout presumably commences the first-person narrative that opens the novel much later in her life. As a result, the narrative voice fluctuates between the child’s point of view, chronicling the events as they happen, and the adult voice, looking back on her childhood many years later. The child’s naïve voice dominates the central plot, allowing the reader to make connections and understand events in a way that the young Scout does not. At the same time, the narrative often digresses into anecdotes or descriptions presented retrospectively, like Scout’s depiction of Maycomb in the first chapter: “Maycomb was an old town, but it was a tired old town when I first knew it. . . . Somehow, it was hotter then . . . [p]eople moved slowly then.” Here, Lee’s language indicates an adult’s recollection rather than a girl’s experience.

Structurally, To Kill a Mockingbird is circular: the story begins where it ends. The first line of the novel introduces Jem’s broken arm, and the novel then flashes back to cover the events leading up to his accident. The narrator uses this device to provide background for the Finch family, introducing the legendary Simon Finch and his three descendants. But at this stage of the novel, the family history is treated as background information, of secondary importance to the private world of the young Finch children. In this way, the first chapter provides only a brief sketch of Atticus, whose importance increases as the novel progresses. Jem and Scout are the center of the story, filling it with their world of imagination and superstition, centered on town myths such as the curious history of Boo Radley and imaginative diversions such as acting out stories from books.

Dill dominates this early part of the novel: he is only a summer visitor, with no connection to Maycomb’s adult world. As this adult world asserts itself later in the novel, Dill fades from the story. For now, however, the novel appropriates Dill’s childhood perspective and only hints at the darker, more adult problems that will intrude on Jem and Scout. One of the central themes of To Kill a Mockingbird is the process of growing up and developing a more mature perspective on life. Correspondingly, the narrative gradually comes to mirror a loss of innocence, as the carefree childhood of this first chapter is slowly replaced by a darker, more dangerous, and more cynical adult story in which the children are only minor participants.

Boo Radley becomes the focus of the children’s curiosity in Chapter 1. As befits the perspective of childhood innocence, the recluse is given no identity apart from the youthful superstitions that surround him: Scout describes him as a “malevolent phantom” over six feet tall who eats squirrels and cats. Of course, the reader realizes that there must be more to Boo’s story than these superstitions imply. Eventually, Boo will be transformed from a nightmare villain into a human being, and the children’s understanding of him will reflect their own journey toward adulthood.