Bart is caught graffiting by Principal Skinner after a tip-off from Martin Prince, the class brain. During an intelligence test later the same day, Bart swaps his paper with Martin's.
After school, Principal Skinner speaks with Homer and Marge in his office. He is interrupted by Dr. Pryor, the school psychologist, who says that Bart is gifted. He believes Bart's boredom in school is the reason for his bad behaviour.
Bart is promtly moved to a school for intelligent children, but does not fit in. After a chemistry experiment goes horribly wrong, he confesses to Dr. Pryor that he is not really a genius.
Back at home, he tells Homer the truth, but points out that it has brought them closer together. However, Homer is still mad and chases Bart through the house.