Sandra witnesses a man strangling a girl. She tells the police about herself, how she arrived in Saint-Tropez and decided to make it there. She first met hippies roaming the clubs and sleeping on the beach, then a playboy, and a man working in a striptease club looking for girls willing to practice lesbian acts for voyeurs. So that was her début in Saint-Trop'. Then she moved on to modelling, dancing as a go-go girl and eventually participating in orgies - all jobs illustrated with scenes where she doesn't appear on the screen. She shared most of her free time with other would-be queens of the night and sun lovers.
Then she met the manager of an oil company who took her on a cruise to Tangiers. Nice parties on board the ship where she met the girl who was to become the victim of the murder she witnessed in the opening scene of the film. The police tell her to stay in Saint-Tropez and she's back to her job at 'La Ponge'. Yet she decides to do it her way and hitch-hikes back to Paris. On the way she's given a lift by a moustachioed man and they spend the night together in a hotel (simulated oral sex but finger actually in pussy!). The man thinks he's met her before. She pretends her name is Monique and on discovering he is a journalist tells him her story. The man is in fact working as a detective for the murderer who kills him after learning that Sandra is on her way to Paris.
Sandra meets Madame Lucienne who runs a call-girl business and gives her shelter from her dangerous life for some time. (Nice sexy sepia shots of the call-girls by the way.) Then she gets into the sexy-clubs business, works at a club called 'The Strip-Poker' and models for 'Studio 69' where the murderer finally finds her.
By now, everyone watching the film should be aware that the murderer is in fact a woman dressed as a man. Sandra notices the ring she had seen on the murderer's finger and asks a blonde girl (Nathalie Zeiger) to take her place with the 'man'. So the blonde goes with the 'man' and soon discovers he is a she called Claude, who seems very attracted to women. They have a private photo session which ends up in bed where Claude turns out to be attracted to blood (her own for the moment) and tries to learn more about Sandra.
Later, in a club, Claude invites Sandra to a show at the 'Love Théâtre'. Sandra goes to the rendez-vous (couple on the stage) and meets Claude dressed as a man who takes her home. She reveals her real sex and plays with a statue in front of Sandra who thinks she must be mad. (Psychedelic scene.) Claude takes out a dildo and plays a little with it (more psychedelics). When somebody calls on the phone (the dead detective?!) Sandra takes the call and Claude tries to kill her. Sandra wins the fight and Claude dies. When Sandra leaves the place dressed in Claude's man's clothes she gets caught by two male nurses who had been asked by Claude's husband to take his wife to a mental institution. Will Sandra be able to escape that new predicament? ... End.