Jack Anderson, star graduate of the Sure-Fire School of Salesmanship in Los Angeles, uses fast-talk and flattery to sell insurance policies to women. Although he is dating Peggy, a nightclub performer, when he meets Ann Rogers, whom he thinks is a nice, decent girl, he falls in love with her and drops Peggy. Jack warns his kid sister Jean, a night-shift telephone operator, against fraternizing with women like Peggy, but when Peggy gets a job at the Club Deauville escorting wealthy men to gambling tables and drinking champagne, she introduces Jean to Deauville's lecherous owner, Jimmie Stuart, and he hires her. Ann is a singer at the club and goes by the name Dolly LaVerne. During Jean's first night on the job, Stuart calls her "Little Miss Innocence," gets her drunk on champagne and tries to seduce her. Ann rescues Jean by pretending Stuart is two-timing her and falling into a jealous rage when she walks in on them. Later, when Jack brings Ann home to announce their engagement, Jean tells Jack that Ann is Dolly LaVerne, Stuart's girl friend, and Jack accuses Ann of being loose, cheap and two-faced. When Stuart hears about the mix-up, he explains all to Jean, who then assures Jack that Ann's stunt in Stuart's room was performed to protect Jean. Jack, sorry for falsely accusing Ann, goes to her home, where her brother Harry, blinded a year before in a plane accident, explains that Ann must work to support them. Jack and Ann then marry.