The story is told in a series of letters written by Charlie, a freshman in high school, to an unnamed “friend.” Charlie doesn’t know the person he’s writing to, and the friend’s identity is never revealed. Charlie is trying to cope with the recent suicide of his only middle-school friend, Michael, and with the death of his beloved Aunt Helen, which happened when Charlie was seven. At the time of Michael’s death, guidance counselors try to help Charlie, but he was still unable to react beyond screaming and crying.
Charlie feels lonely and outcast in high school: he doesn’t really have any friends, and he swings between being very quiet and beating up kids who tease him. Charlie’s sister is a senior in high school, and Charlie’s brother graduated last year and now plays football at Penn State. The family watches the brother’s games on television.
Charlie reads To Kill a Mockingbird in English class and loves it. Bill Anderson, Charlie’s English teacher, notices that Charlie is passionate about reading and writing, and he assigns Charlie extra books to read and extra essays to write. Charlie witnessed his sister’s boyfriend, who seems like a sweet, artsy guy, hit her hard across the face. But she makes Charlie promise not to tell their parents what happened, so he doesn’t, even when the boyfriend continues to come over and pretend to be nice.
Bill gives Charlie a C on his To Kill a Mockingbird essay, even though it’s clear that Charlie is a gifted writer, because Bill wants to push Charlie and help him improve. Charlie reminisces about watching television with his family, which reminds him of his Aunt Helen. The finale of M*A*S*H is emotional for Charlie’s family, since it marks the end of an era.
Two seniors befriend Charlie: Patrick, whose nickname is “Nothing,” and Sam, Patrick’s stepsister. Charlie immediately develops a crush on Sam, but he’s too shy to act on it. As it turns out, Patrick is secretly dating Brad, the closeted quarterback of the football team. Later that week, Charlie tells Sam that he had a sex dream about her, because he wants to be honest, and she laughs. Patrick gives Charlie advice about dating girls, including not telling them about one’s sex dreams. Charlie confides his insecurities about dating to Bill, and he tells Bill about the boy who’d hit his sister. Bill says, “Charlie, we accept the love we think we deserve.” When Charlie goes home that night, he realizes immediately that Bill has called home and told his mom and dad about his sister’s boyfriend. Their parents forbid the sister to see the boyfriend, and the sister calls Charlie a freak.
Patrick has taught Charlie about masturbation, and Charlie’s been doing it more and more. Charlie tells the “friend” that he’s trying to participate more in life, as Bill had advised him to do. He goes the homecoming football game and sits with Patrick and Sam, who invite him to a party after the game. Charlie has a flashback to a big party that his brother had had at their house once, where he accidentally watched a girl get date-raped. Charlie hadn’t realized that it was date-rape until just now, when he talked about it with Patrick and Sam. After the homecoming dance the next day, Charlie punctures the offender’s tires, even though it’s several years later.