Through a series of letters to his father, a private investigator, fifth-grader PJ "Clueless" McGee tells of his efforts to discover who stole macaroni and cheese from the school cafeteria.

When Clueless learns that the scribble on the cowboy hat sent by his father is actually the autograph of teen idol Junior McFiddle, everyone in school suddenly wants to be Clueless' friend--and they want his hat.