Here's a breakdown:
* Chapter 17: The trial begins with the jury selection and the introduction of the prosecution's case.
* Chapter 18: The prosecution presents its witnesses, including Mayella Ewell and Bob Ewell, who both give conflicting testimonies.
* Chapter 19: Atticus Finch, the defense attorney, begins presenting his case. He calls Tom Robinson to the stand and challenges the prosecution's claims.
* Chapter 20: Tom Robinson gives his testimony, revealing the truth about the incident and the racial prejudice he faces. Atticus confronts the witness, Mr. Gilmer, exposing the inconsistencies in his arguments.
* Chapter 21: The trial concludes with the jury's guilty verdict, despite overwhelming evidence of Tom Robinson's innocence. The chapter ends with the shock and outrage of the courtroom audience.