Narrator and main protagonist Bobby Phillips is 15. He resents how his parents lord over him with their advanced, scholarly knowledge. His mom, Emily, is a literature professor at the University of Chicago, and his dad, David, is a scientist at the university’s FermiLab. Bobby attends an elite private school there that’s open to faculty children. Except for playing trumpet in the school’s jazz band, he doesn’t much care for school. He feels invisible there, unwanted by the popular kids, but he’s also smart and inquisitive: “I read all the time and I remember everything. I know a few things too” (13).

Bobby wakes up one morning to find that he’s become invisible. Suddenly his everyday life is in an uproar: He can’t reveal his condition, lest the government take him from his parents and run experiments on him. Feeling trapped at home, he strips off his clothes and goes where he pleases, completely unseen by others. He meets Alicia, a girl recently made blind in an accident and who feels herself to be invisible. Their shared viewpoint forms the kernel of a close friendship, and their struggle to get past their own fears, which interfere with the relationship, provides much of the story’s plot development.