When does Scout think she and Jem first began to part company and why?
This happens in Chapter 6, when Jem determines to return to the Radley Place at night to retrieve his pants which were caught on the fence when he, Dill and Scout were fleeing the place earlier. They had gone up to try and get a glimpse of Boo but instead had been chased away by gunshots. Scout is terrified that Jem will get killed, but his main worry is that, if he leaves his pants there, Atticus will get to know of his escapades and might whip him. He wants to avoid the possibility of this at all costs. Scout can't begin to understand his attitude. She is still consumed by her childish fears of the Radley Place but Jem is now moving past this stage, and is more concerned about his relationship with his father than about getting chased by phantoms. Scout, being a child, can't appreciate this, but she senses that Jem is beginning to leave childhood games, fears and ideas behind.