The fourth chapter is set in Medardo's hometown of Terralba. The Viscount has just got back there from the Boehemian battlefields were his body has been halved. The chapter takes place immediately after the death of Medardo's father when Medardo decides to go out from his castle. His wet-nurse orders some servants to follow him and they discover that the Viscount halves all the things that he encounters, even some poisonous mushrooms. Suddenly it become clear that the half of Medardo that has come back is his bad half. In fact, he has given the halves of the poisonous mushrooms that the servants don't find immediately to his nephew (the narrator of the story) who was only a child at the time. In addition, during the course of chapter 4, Medardo acts as a judge for several trials and condemns to the death sentence all the parts involved in it including the police officers because they had taken action too late.