Eddie has a lot to deal with. His father and his best friend, Billy, are both killed accidentally within a month, and Eddie is the one who finds both bodies. Now he's being haunted by Billy, who also is the narrator of the story. His mother is being drawn further in to a fundamentalist church, led by Reverend Tarter, who is a busy guy: he is also an English teacher at Eddie's school, is trying to manipulate Eddie into joining the saved, and is working with his congregation to get a book banned at school.
That book, Warren Peece is a fake book by the real author of this book, Chris Crutcher, who becomes a character in his own book when he gets involved in the effort to stop the banning. And that book happens to be the only meaningful thing Eddie has found to help him deal with his grief. So Eddie, though he hasn't spoken since he found Billy's body, is determined to save the book, and take down the Reverend at the same time.