Meanwhile, Mr. Ewell threatens Atticus and other people connected with the trial because he feels he was humiliated. He gets his revenge one night while Jem and Scout are walking home from the Halloween play at their school. He follows them home in the dark, then runs at them and attempts to kill them with a large kitchen knife. Jem breaks his arm, and Scout, who is wearing a confining ham shaped wire costume and cannot see what is going on, is helpless throughout the attack. The elusive Boo Radley stabs Mr. Ewell and saves the children. Finally, Scout has a chance to meet the shy and nervous Boo. At the end of this fateful night, the sheriff declares that Mr. Ewell fell on his own knife so Boo, the hero of the situation, won't have to be tried for murder. Scout walks Boo home and imagines how he has viewed the town and observed her, Jem and Dill over the years from inside his home. Boo goes inside, closes the door, and she never sees him again.
Finch, as a lawyer, is asked to take a legal case that involves defending Tom Robinson, a black man who has been accused of abusing a 19-year-old Caucasian female named Mayella Ewell. Eventually, the news of his accepting the case spreads around town and puts Atticus in a negative light, leaving Jem and Scout angry about it. Atticus forbids Scout from fighting with the other kids. Once Walter Cunningham Jr., a child that Scout fought with, is invited to dinner, Atticus says that it is "a sin to kill a mockingbird", referring to the temptations to go after birds once children got their first guns.