In Chapter 14 of Harper Lee's novel To Kill a Mockingbird, Dill has run away from home and taken refuge under Scout's bed, where he hid for two hours. Jem, clearly understanding the gravity of the situation, insists that Dill's mother ought to informed of her son's whereabouts despite Dill's obvious pleasure in the thought of people back home searching for him. It is then that Scout comments on Jem's decision to inform Atticus of this new development:
Dill’s eyes flickered at Jem, and Jem looked at the floor. Then he rose and broke
the remaining code of our childhood. He went out of the room and down the hall.
“Atticus,” his voice was distant, “can you come here a minute, sir?”
Scout is aghast that her brother would violate this childhood 'code of conduct' that precluded the provision of sensitive information to adults, especially information regarding their own conduct and that of Dill, their closest friend. The episode, however, serves to illuminate the degree to which Jem has matured emotionally and is ready to make that transition towards adulthood.