Chapter Twenty-One - Mr. Dobbins harshness is a product of his desire to build up his reputation by pushing his students to better performance. He desires the admiration of the crowd, and he is willing to hurt others to try to get what he wants.
Chapter Twenty-Two - Tom joins the cadets not because he believes in their moral stand but because he likes how being a part of the group makes him look. While, for Tom, this is literal -- he likes their outfits.
Chapter Twenty-Three - The murder trial finally begins. They all agree that Injun Joe would kill them, so they continue to help Potter in small ways, bringing him tobacco and matches.
Read by John Greenman