The book recalls the murder of Doctor Robinson and the murder trial is coming up shortly.  Muff Potter is the talk of the town, and so far Tom Sawyer and Huckleberry Finn are the only two people who know that Injun Joe was the real murderer.  Tom begins to feel sad a guilty again now that he his reminded of the incident.  He finds Huckleberry Finn and talks to him about it in hopes that it will give him some comfort.  They reassure each other that neither of them has told a soul about what they know.  They then swear again to not tell anybody, just to make sure.  They then go and visit Muff Potter while he is in his cell, and talk about old times when Muff used to go fishing with them and such.  The next day was the court date and Tom decides to attend.  Many witnesses were called to the stand  to testify against Muff Potter.  Some said that they had seen him with the knife, others said that they saw him washing the blood off his hands in the river, and others said that they saw him with a guilty look.  But then all of a sudden, they called Tom to the stand.  He was scared to death but he went up onto the stand anyway.  He performed the oath and was then asked questions about where he was and what he had seen that night.  He told them everything that he knew.  He told them where he was and who the real murderer was.  Right then, Injun Joe jumped out of the window in the court room and ran away!