In Chapter 20 of the novel To Kill a Mockingbird, what happens when Scout and Dill return to the courthouse?

At the beginning of Chapter 20, Scout and Dill talk with Dolphus Raymond outside of the courthouse. After Dolphus explains why he feigns alcoholism, Scout realizes that they are missing Mr. Gilmer's cross-examination. When they return to their seats, Atticus is half-way through his speech to the jury. Jem tells Scout that Atticus has just finished going over the evidence and has made the case perfectly clear. Jem believes that Atticus will win the case.

Scout and Dill arrive just in time to hear Atticus' closing remarks. Atticus informally unbuttons his vest and loosens his tie before he begins his speech. He tells the jury that "this case is a simple as black and white," and should never have come to trial in the first place. (Lee 271) Atticus explains how the testimonies of Bob and Mayella contradict, and how the state has not been able to produce any medical evidence to convict Tom Robinson. Atticus tells the jury that Mayella felt guilty because she broke a "time-honored code of society," and that her father beat her as a result. (Lee 272) Atticus mentions that the jury's decision should not be based on the assumption that African Americans are all evil. He quotes Thomas Jefferson and urges the jury to review the case "without passion," and restore Tom Robinson to his family. Atticus understands that the jury members harbor prejudice against African Americans and encourages them to judge the case based on the evidence and testimonies provided, and not Tom's skin color.