Springfield is suffering an economic slowdown, so the townspeople decide to legalize gambling. Mr. Burns builds a casino on the waterfront, and hires Homer as a blackjack dealer.
When Marge finds a quarter on the floor at the casino, she starts gambling and keeps winning. Soon she is addicted. Lisa worries about her, and makes her promise to help her with a costume for the upcoming Geography Pageant at school.
But when Marge doesn't show up to help her, Homer goes to the casino and confronts her. Marge admits she has a gambling problem and leaves the casino with Homer.