The final chapter of the book begins where chapter 30 left off, with Boo and Scout together on the porch. Scout doesn't feel weird or scared, and she treats Boo like she would anyone, respectfully and kindly. 
They go inside to say good night to Jem, and then Boo asks Scout if she will walk him home, and she does. Scout reflects how Boo always gave them stuff like a normal neighbor would do, but they never gave anything in return, and she feels bad about it.
While Scout is on Boo's porch, she is able to see his world and understand him a bit better. She sees how Boo saw them, and what he thought through all of it. 
When Scout gets home, she finds Atticus reading by Jem's bed, and asks how he is doing. Jem is sleeping, and Atticus tells her he is doing fine. 
Atticus reads Scout The Gray Ghost, and she falls asleep while listening to it. It's about a boy that is suspected of ruining a group of boys' clubhouse, but he's never been seen, so they don't know who to go after. Turned out, he was actually really nice when they finally met him.
Scout thinks about this as she falls asleep, and Atticus tells her most people are nice once you get to know them, and this applies to Boo Radley, because before it was assumed he was a terrible, scary person, but really, he is a kind and gentle person.