Chapter 15: Sheriff Heck Tate and a posse of townspeople congregate on the Finch's front yard to discuss moving Tom Robinson to the Maycomb jail in preparation for his impending trial. The children overhear only pieces of the conversation but it is apparent that Atticus and the other folks are worried about the trouble the move might cause. Atticus says nothing about the issue when he returns to the living room but the following day, Sunday, he mysteriously leaves after supper with a light bulb and an extension cord. The children notice he has also taken his car so they decide to find Atticus in town after Aunty thinks they've gone to bed.
That night, Jem, Scout, and Dill sneak out of the house and walk into town. Sure enough, they find Atticus's car parked near the jailhouse and when the move in that direction they find Atticus sitting in front of the jail reading a book under the lightbulb he had brought. Scout's first instinct is to run to him but Jem fears Atticus would not approve of their leaving the house without permission. Right as the three decide to return home several cars pull up in front of Atticus. The children stay to watch. A group of men, mostly farmers, exit the cars and approach Atticus with guns and weapons. They want to get to Tom Robinson but Atticus stands in their way. The tension between the farmers and Atticus grows as the men confront one another. After several minutes Scout cannot handle the tension anymore so she leaps from her hiding place and runs to Atticus's defense. The other children follow her. When Atticus sees the children he demands that Jem take Dill and Scout home but Jem refuses. Scout, meanwhile recognizes Walter Cunningham's father (Walter Sr.) in the crowd and proceeds to engage him in conversation. Embarrassed that Scout has singled him out, Walter refuses to answer Scout's questions. Finally, Scout turns to Atticus and asks him why the men won't talk to her. She has succeeded in diffusing the tension and she has reminded Walter and the other farmers that they are all neighbors and friends. Walter motions the group to retreat and acknowledges Scout has he leaves. Grateful to the children for intervening, he lets them return home without reprisal. Alone again in front of the jail, Atticus mentions to Tom that they farmers have left and notifies B. B. Underwood, who had been hiding above Atticus with his gun ready to fire on the farmers, that all is clear.
Chapter 16: Tom Robinson's trial begins. So many people pour in to Maycomb to watch the trial that the town takes on a festive atmosphere. Lee devotes this chapter to describing the festive scene and introducing a new character, Dolphus Raymond. Dolphus, a white man, is the only white person in the county who associates socially with black people. In fact, he married a black woman and is the father of bi-racial children. Dill, Scout, and Jem, who secretly left Aunty's supervision to watch the trial, marvel at Dolphus and wonder why he would choose to socialize with black people and how he manages to do so in a county governed by social rules and barriers.
The trial starts but the children, who enter the courthouse late, cannot find seats in the lower section designated for white people. Reverend Sykes, the preacher they met when they visited Calpurnia's church, invites the children into the upper section designated for black people. The children gladly accept the invitation and settle in for the morning proceedings.