: The book tells the story of four wealthy libertines who embark on a journey to a remote castle where they engage in a systematic and escalating program of sexual perversions and violence on a group of young women and boys they have kidnapped. The narrative is structured around the libertines' recounting of their past sexual exploits, with each trying to outdo the others in depravity.

To understand the film, one must first understand the source material. In 1785, the Marquis de Sade, imprisoned in the Bastille, wrote The 120 Days of Sodom on a continuous scroll of paper. The novel was a systematic catalogue of sexual perversion and cruelty, designed to shock the moral fabric of the 18th-century aristocracy. It remained largely unpublished until the 20th century due to its extreme content.

The film depicts the human body as a mere commodity, demonstrating the total "annulment of the personality" under a totalitarian regime. Critical Legacy and Warning

Rather than a direct adaptation, Pasolini transposed the setting to the fascist puppet state of the Republic of Salò in northern Italy during the final years of World War II. The film's plot is simple and horrific: in 1944, four powerful libertines—the Duke, the Bishop, the Magistrate, and the President—round up a group of nine adolescent boys and nine girls. They take them to a grand villa, where, over the course of 120 days, they subject them to a brutal regime of systematic sexual torture, sadism, psychological degradation, and eventual murder.