Before the initial credits appear, Sadie (Analeigh Tipton) is engaged in an intense sexual act with her ex-boyfriend, bearded Alex (Jakob Cedergren). Interposed are brief back-shots of her in various sexual proclivities.
After the credits, Sadie is the guest of honor at a book tour in Turin, Italy, where, in describing her autobiography, she relates her sexual feelings to a gathering. Her latest boyfriend is Thierry (Valentin Merlet). After the gathering, Alex, who is around, invites her to a seamy club, where she meets Francesca (Marta Gastini), who is as attractive as Sadie is. Alex invites Sadie and Francesca to his business-partner's villa, really a 17th century walled fortress decorated with magnificent art and statues. For some insipid reason she accepts.
At the villa Sadie and Francesca take drugs (pills) with alcohol. Sadie develops a lesbian relationship with Francesca. Meanwhile, bizarre rituals occur and masked guests attend wearing strange attire. There is a ritualistic killing, a "black magic" type of ceremony. Is it all a dream? Bloodstained fingers say no. When Sadie questions Alex the next day, he says she should have known what she was getting into.
Thierry then appears at the villa for some reason, but is rebuffed by sexually-charged Sadie. Later it is Thierry who is tied up and on the sacrificial agenda. Sadie is given a knife. What will Sadie do? Will she ever escape her dilemma? Is her name a derivative of sadism?
This is an artsy type of film like "Last Year at Marienbad" (1961), an entirely different film, but also difficult to understand. Despite its colorful sets, erotic scenes, and on-location filming, "Compulsion" makes little sense. The screenwriting and plot are weak, and the film unmemorable.