Halloween night had been a rough one for Atticus. He was already tired from spending a week in Montgomery, and he decided to skip the school pageant. Then he learned of the attack on his children. Atticus was frantic, concerned about Jem's injury and his son's possible connection with Bob Ewell's death. It was one of the few times in the novel that Atticus wasn't thinking clearly. Even though it was Boo who brought Jem into the house, Atticus didn't initially think that Boo was connected with the death: Atticus thought Jem had killed Bob, and it took a bit of convincing from Sheriff Tate before he was convinced that Boo--and not Jem--had killed Bob. Atticus then realized that Jem may have to testify in support of Boo, giving him even more worries. But Sheriff Tate's decision to call Bob's death self-inflicted solved the problem. Boo and Jem were off the hook, but Atticus still didn't like going along with Tate's way of thinking. It was Scout who eased Atticus' mind, telling him that the sheriff had made the right decision, keeping Boo from being dragged through a public investigation.
"Well, it'd be sort of like shootin' a mockingbird, wouldn't it?"
It was only then that Atticus' "youthful step" returned. Jem would recover from his injuries, Scout was okay with the sheriff's secret, and none of them had to worry about Bob Ewell again.