Over the course of their conversation, Proctor makes a developing series of decisions and agreements with Elizabeth.
After initially discussing the trials, Elizabeth urges Proctor to inform the court that Abigail said what the girls were up to was nothing more than "sport". Elizabeth presses Proctor not to wait, saying, "...let you go tonight."
Proctor instead agrees to think about what to do. He says that now that the town is in such a state, thinking Abigail to be a saint, the task of painting her as a fraud will be difficult.
Later in the scene, Proctro agrees to find Ezekiel Cheever and put a stop to fraudulent proceedings in Salem. Finally, he agrees to find Abigail and tell her clearly that no matter what happens to Elizabeth, he will never return to Abigail.
This agreement is made after Proctor and Elizabeth are told that Elizabeth has been accused by Abigail. Elizabeth believes that Abigail wants her dead and out of the way.