Springfield suffers an economic slowdown. The government closes Fort Springfield and Mr. Burns lays off employees. At a town hall meeting, Principal Skinner suggests that gambling be legalized to raise money for the town. The plan is adopted and things change overnight.

Mr. Burns builds his casino in Springfield's boardwalk section, and employs Homer as a blackjack dealer. Bart converts his treehouse into a casino and encourages other kids to gamble. Marge slowly becomes addicted to slot machines and ignores her family. Mr. Burns grows even richer and, like Howard Hughes, becomes paranoid about germs.

Lisa senses that Marge has a gambling problem. She makes Marge promise to help her with her costume for the upcoming Geography Pageant, but Marge fails to return home in time from the casino. She finally admits to Homer, and herself, that she has a serious gambling problem.