MARQUIS DE SADE: JUSTINE

In Paris during the late 18th-century, Justine (Romina Power) lives with her sister Juliette (Maria Rohm) in a convent. When they learn of their father's death, they are ordered out of the convent with their father's remaining money - 100 coins, which is not enough to survive. Juliette takes Justine to a friend, Madame de Buission, a brothel owner who requires the girls to work as prostitutes in return for accommodation. Justine refuses and leaves the brothel with her gold while Juliette stays. Juliette and a fellow prostitute named Claudine (Rosemary Dexter) kill Madame de Buisson and one of her clients, stealing her gold and making their escape.

A man named Du Harpin (Akim Tamiroff) agrees to let Justine stay for free if she serves as his maid. Du Harpin's master forces himself on Justine. She escapes but is instructed by Du Harpin to steal the man's gold amulet. Justine refuses. While she is asleep, Du Harpin places the amulet in Justine's belongings to frame her, out of spite for her having refused to steal it for him. The next day, police find the amulet in Justine's belongings. Justine is taken to prison where she meets Madame Dubois, a virago sentenced for execution. Madame Dubois, impressed by Justine's innocent looks, includes her in an escape plan. The next day, Madame Dubois and Justine escape the prison safely.

While hiding out in a forest, Madame Dubois (Mercedes McCambridge) accepts Justine as part of her group. The male members of the group attempt to rape Justine. She escapes and faints near the house of a painter named Raymond (Harald Leipnitz), who eventually makes her his model. They fall in love and live happily until the police arrive at Raymond's home, searching for Justine, and she must escape again.

While on the run, Justine becomes a personal attendant to the Marquise de Bressac (Sylva Koscina), whose husband Marquis de Bressac (Horst Frank) asks Justine to kill his wife or be framed for a crime. The husband adds poison to the wine on his wife dinner tray, but the wife tests the food on the tray on the dog and the dog falls dead. Justine and the Marquise become terrorized after witnessing the death of the dog poisoned by the food they were about to eat. Terrified and revengeful Marquise attempts to poison her husband, but he clandestinely switches the glasses and tricks her into drinking his poisoned wine, thus killing her dead. In the following sadistic punishment of Justine, the Marquis brands the letter 'M' for 'Murderess' on Justine's naked chest between her bare breasts.

Humiliated and branded Justine arrives at a sanctuary where four ascetics, who are pretending to be religious and righteous and are posing as clerics living a life of meditation and study. Oblivious Justine asks for sanctuary there and is instantly accepted by a secret sadistic Order chaired by devious Father Antonin (Jack Palance) who is constantly drunk. She soon learns, however, that the four men are sexual deviants whose four other female servants are, in fact, former prostitutes and now serving as sex slaves. Justine ends up chained and tortured in the dungeon. Father Antonin drinks a large chaise of alcohol praising Justine's sense of pleasure that is enduring her suffering, to which frightened Justine blindly agrees under pressure. Pleased at having learnt their philosophy so swiftly, Father Antonin, whose intoxication robs him of any sense of compassion, now plans to "release" Justine by killing her in torture during a ritual of sticking many sharp needles under her naked skin and hanging her in chains. The ceremony of hanging Justine goes awry when Father Antonin tortures her with a burning cross and the fire gets to the skin of her naked breasts. So Justine, who could not sustain the unbearable pain, suddenly screams and shakes her chains while other slaves provide help to her and assist in her escape through a tunnel during the disastrous commotion.

Raymond finds Justine unconscious and half-naked lying flat on the road and takes her to a nearby city. There, Madame Dubois finds Justine and takes her to work as a nude show performer. During the show, Justine's brand "M" on her bare chest becomes visible to the crowd and causes an uproar with accusations of her being a murderer. As she is being taken away by the police, she is spotted by her sister Juliette, now a mistress of a powerful Minister of the King of France. The Minister stops the police from taking the girl to prison and offers her protection. The two sisters reunite in tears. Juliette describes her wicked life as empty and says that Justine will earn her reward of two million francs for a virtuous life despite her sufferings.

Juliette takes Justine away to live with her in her palace and finally, Justine and Raymond are seen walking away peacefully.