Alexander's little brother, Benjamin, doesn't do things the way Alexander thinks he should. He would rather stare at the wall than play with Alexander. And instead of talking, he just wiggles his fingers and rocks. Alexander knows it's wrong, but he can't help but feel embarrassed when one of his friends calls Benjamin a "wacko."
When Benjamin's family learns that he has autism, they hire special teachers to teach him how to listen and talk and play. Alexander is glad--he just wants Benjamin to grow up faster. While Benjamin works with his teachers, Alexander works through his feelings of disappointment and jealousy. As time passes and each boy grows, Alexander discovers that Benjamin isn't just his brother--he is also his friend.