The-girl-formerly-known-as-Scout arrives in Maycomb, Alabama, via train. Jean Louise is traveling from New York City to visit her 72-year-old father, Atticus.
Atticus, crippled by rheumatoid arthritis, lives with his sister, Alexandra, and has taken on an apprentice at his law firm, Henry Clinton, who is Jean Louise's childhood friend and present-day beau (that's Southern for "future hubby").
Jean Louise and Henry visit Finch's Landing, the estate of Jean Louise's grandmother. Or should we say, former estate. While she's been gone, her family sold it to a local hunting club. And no one told her. She's upset that her world is changing without anyone telling her.
But what upsets her more might be the fact that her world hasn't changed—it never was what she thought it was. Her foundation is shaken when she finds a racist pamphlet in her father's office, hears her Aunt defending racist beliefs, and sees both Atticus and Henry at a Maycomb Citizens' Council meeting. (The Citizens Council is basically KKK, Jr.)
Jean Louise takes to her bed, where she has a variety of flashbacks on her childhood—playing with her friend Dill (who now lives in Italy) and her brother Jem (who now lives in the cemetery, because he's dead). She then hears about an accident—a black man hit a white man, who drunkenly stumbled in front of his car. Atticus agrees to defend the black man because he is the Finch family former cook, Calpurnia's grandson.
Jean Louise visits Calpurnia, and is offended when the woman talks to her as she talks to other white people. So Jean Louise decides she has to confront her father about the racist pamphlet and his presence at the Citizens' Council.
During their argument, Atticus doesn't waver from his beliefs at all. He believes what he reads in the racist pamphlet, and he disagrees with the recent Supreme Court decision on integration. He worries about black people taking power and winning government positions. Even though Jean Louise agrees with Atticus that the Federal Government shouldn't overrule States' Rights, she cannot handle his racist attitude.
She calls him "no damn better" (17.145) than Hitler. She says she "despise[s] [him] and everything [he] stand[s] for" (17.149). And she calls him a "double-dealing ring-tailed old son of a b****" (17.153).
So yeah, she's angry.
After she leaves, Atticus calls his brother, Dr. Jack Finch, to slap some sense into his daughter. And he does. Literally. He backhands Jean Louise so hard, we're surprised he doesn't break her teeth.
He tells Jean Louise that she is a "bigot and he's not" (18.107) because Atticus challenged her opinions, and she wouldn't listen to him. He tells her how important it is to listen to people of different opinions, even if those opinions involve slavery being "incidental" (14.164) to the Civil War (or the "War Between the States") and that black people are simply inferior to whites. Uh...
So she decides to. She reconciles with her father. He says he's proud of her for standing her ground (even though that's how her uncle defines bigot), and Jean Louise says she loves her father "very much" (19.26).
At least until a third manuscript is found hidden in Harper Lee's recycling bin.