In busy Times Square, New York, many gamblers are discussing their various bets. The word on the street is that one of the greatest gamblers, Sky Masterson, is in town and a hard-up man, Nathan Detroit, wants a sure bet to secure money for a big craps game. He bets Sky that he couldn't take Sarah Brown, a missionary who warns the gamblers of their evil ways, on a date in Havana. Accepting, he quickly finds out that she will not be an easy target. Meanwhile, Nathan's fiance of fourteen years and a night club dancer, Adelaide, is still hoping that she and Nathan will ge t married soon. While Sky and Sarah are in Havana, he realizes that he is falling in love and must tell her the truth about the bet. When they return to New York, Nathan has the game all set up and fixed by due Big Jule, a gangster from Chicago. Both Adelaide and Sarah are heartbroken by their gambling lovers but at the very end, both Sky and Nathan realize that their ladies are worth losing a bet and they get married.