After the revelation of Ewell's death, Heck Tate asks Scout to recount everything that happened. He asks her questions along the way, wondering what she shouted and if Atticus heard it, which he didn't. Heck then explains that there were perforations on Ewell's clothes and skin, which he realizes were made by the chicken wire from Scout's ham costume. He calls Ewell a coward, and Atticus, still a little in shock, says he never thought Ewell would come after his kids. He was, of course, drunk at the time, which probably made it easier for Boo to pull him off Scout. He's the one who saved them; Scout didn't realize it before, but understands that it's him when she looks him in the eye. She says, "Hey, Boo," and nearly cries.

Idiom

Atticus uses an idiom when he says Ewell was "out of his mind," meaning crazy.

Simile

One example of this is Heck's assertion that if we always followed our premonitions then "we'd be like cats chasin' our tails."

Themes

Courage. Lee continues to build on the theme of courage by revealing that Boo was the one who saved the kids and that he came out of his house for the first time in what might be years in order to do so. This kind of courage doesn't stem from moral fortitude, but rather from the raw human desire to protect those we love. In this sense, Boo is like Atticus in that he's extremely protective of Scout and Jem, but unlike him in that he's willing to kill a human being in order to do it. Atticus never even considered the possibility of Ewell attacking the kids, which is perhaps his only failure in the novel.

Cowardice. Hand in hand with courage is cowardice, which is what leads Ewell to attack Atticus's children in the dead of night rather than face Atticus man to man in daylight. Ewell's actions are both furtive and malicious and evidence a weak moral character that made Ewell a pariah during his lifetime. His attack on the children figures him as an entirely worthless human being.