The novel is about three years in the life of the Finch family: Atticus and his son Jem and daughter Scout. Atticus is a lawyer and the central incident of the novel is when he defends a black man, Tom Robinson, against the charge of raping a white girl.
The story is told in the first person [first person: The 'I' or 'we' used by a narrator who is a participant in a narrative, in contrast to the third person - 'he', 'she' or 'they' - of a narrator who is not directly involved. ] by Scout Finch, a young girl - so we see things from her point of view, and sometimes we need to reinterpret what she tells us.
Jem (aged 10) and Scout (aged 6) meet Dill (aged 7), who has come to stay with his aunt in Maycomb during the summer vacation. Dill becomes interested in 'Boo' Radley, a recluse who lives next door to the Finches and whom they have never seen. A myth [myth: A traditional story which is more or less universally shared within a community; an idea which is widely held but not true. ] has grown up locally about Boo and the children are scared of him. It is Dill's idea to make Boo come out.
After that vacation, Scout starts school. Since she can already read and write, yet is told she is doing them wrongly by her inexperienced young teacher, she takes an immediate dislike to school. She gets into trouble when she tries to explain to her teacher why Walter Cunningham, from a very poor family, cannot borrow money for lunch as he will not be able to pay it back. Jem invites Walter to lunch with them.