Esperanza is a nun who turns into a daring subversive named Brenda after mistakenly eating hallucinogenic mushrooms. After breaking into a high society party, Brenda and five young "popis" engage in misdeeds in Mexico City, including robbing a Sanborns to steal five chocolate ice creams and one strawberry ice cream. The adventures of Brenda and her henchmen are hampered by the stubbornness of the commissioner of the International Surveillance Agency, who is also in love with the "dangerous subversive."