Proctor tries to get Mary Warren to tell the court and Mr Hale that Abigail and the girls are faking it, and aren't really seeing those with the devil. She does and is asked for proof however it only puts herself in more danger.
Mary runs and then denies her words and the accusation of Abigail and the girls being guilty. She then accuses John Proctor of communicating with the devil and he is found under trial.
John is taken into the court room and questioned. He then tells the court Abigail is a liar and to try provide evidence admits to the affair he had with Abigail, and that he committed an act of lectury.
They get Johns wife, Elizabeth into the court room about if she is aware of the affair, and although she is denies as she is not told if the court knows, and wouldn't want to endanger her husband or his live.
John is put in prison and told he can only save his life if he admits to contacting the devil. He 'admits' but decides that his name is too important and would rather die a good man that survive on a lie.
John is found guilty of adultery and witchcraft, therefore is sentenced to death and hung.