Johnny Lamb runs a covert casino at a Miami farm, where Lucille Sutton asks him to take her jewelry in exchange for a bet, as she hopes for a windfall with which to pay her mortgage. Knowing she cannot win, Johnny refuses to accept her jewelry, and after beating up gambler Slick Doran and his compatriots for holding up his dealers, Johnny takes Lucille home. He is so impressed with her mansion that he goes into partnership with her, opening a sophisticated casino in her house, despite resistance from his friends Bicarbonate, Honeysuckle and Saratoga, who believe she is a snob who will ruin him. They are so convinced of Johnny's ultimate ruination, that they hire con artists Gertie Malloy and Dictionary McKinney to impersonate socialite Nancy Carstairs, and her uncle Col. Evelyn Carstairs, to seduce Johnny and then dump him, hoping this will rid him of Lucille. Ensnared by Gertie, Johnny asks Lucille to help him to improve his manners to impress his new girl friend. Lucille complies, although she has fallen in love with Johnny herself. Lucille discovers Gertie's ruse soon enough, however, and Gertie and Dictionary plan to get out of town quickly by pretending Gertie has fallen ill and needs to go to a warmer climate. Convinced that the "Carstairs" are down on their luck, Johnny plans to loan them fifteen thousand dollars. Saratoga, Bicarbonate and Honeysuckle mistakenly believe the money is for Lucille and confront her, but she is tired of their insinuating behavior and warns them to watch out for Gertie, rather than her. When Johnny discovers that a family heirloom of the "Carstairs" is worthless, he realizes he has been tricked and exposes Gertie and Dictionary as frauds, after which he hears of his friends' deal with them. Johnny fires Saratoga, Bicarbonate and Honeysuckle, believing they framed him for his money. Lucille's unrequited feelings for Johnny prompt her to ask him for her final check that night. Johnny, however, has had a change of heart and now wishes to operate a legal, daytime business. Within earshot of Johnny, Saratoga, Honeysuckle and Bicarbonate apologize to Lucille for their mistrust, and after Johnny and Lucille accept their apologies, and Lucille leaves. Johnny suddenly realizes that he loves Lucille and goes after her.