The film opens in 1968 at St. Anne's Academy, a California Roman Catholic school, where a young girl named Deloris Wilson is scolded by Sister Immaculata (Lois de Banzie) for wisecracking and disobedience. The setting then changes to the present day, where Deloris (now going by the surname Van Cartier) is a lounge singer in a 1960s-themed act called The Ronelles (a parody of The Ronettes), who sing at The Moonlite Lounge of the Nevada Club in Reno, Nevada, run by her boyfriend, the mobster Vince LaRocca. After Deloris walks in on Vince having his chauffeur Ernie executed for betrayal, Vince orders his two henchmen Joey and Willy to kill her as well. Deloris flees Vince's casino to the local police station where Lieutenant Eddie Souther suggests she testify against Vince if he can be arrested and tried, but for now, she should go into witness protection until the time comes.