Ópalo de fuego: Mercaderes del sexo (1980)

Following a theft, two inseparable friends, Cécile and Brigitte, are sentenced to a year in prison. Cabaret performers, they work civilian gigs as dancers and strippers under the name “Duo Lesbos.” But the police soon transfer the two women to an American prison, where a fake police officer—who is none other than Senator Connolly—asks them to perform for him, then offers them reduced sentences in exchange for a mission. They must infiltrate the Flamingo, a club in Palma, Majorca, to investigate the disappearance of beautiful, famous young women. Cécile is specifically supposed to keep an eye on a villa opposite the hotel where she will be staying and take photographs, which she will then give to Agent Milton without telling her partner. But the duo discovers that the Flamingo is actually a front for a sex-slave operation, where the missing women are forced into prostitution. The ring is run by a certain Madame Forbes, who hypnotizes her victims with an opal she wears on her finger before selling them to extremely wealthy clients… When Cécile falls into the kidnappers’ clutches, Brigitte has no choice but to save her.