In chapter twenty-eight of To Kill a Mockingbird discuss the attack and the events that follow.

The attack occurs after the pageant. It is extremely dark
outside and the kids feel a little scared but think may be it is Cecil Jacobs who is
trying to scare them. They feel as if they are being followed. Once under the coolness
of the Radleys tree they can tell they are being followed. Then, because it is so dark,
we have to rely on Scout's senses to tell us what happens. She feels her costume
crunched on her, and then something frees her and she hears Jem's arm crunch. Then more
of a scuffle ensues. Something defeats the attacker and she believes it is Jem. However,
she sees a man later carrying Jem's body to the house, and finds an unconscious man who
smells like whiskey under the tree. We learn that this man was Bob Ewell from Heck Tate
at the end of the chapter and that there was a kitchen knife sticking up under his ribs.
Boo Radley carried Jem to the safety of the Finches home.