Sandra, her husband Samuel, and their son Daniel live a secluded life in a remote town in the French Alps. When Samuel is found dead, the police question if he was murdered or committed suicide and Sandra becomes the main suspect. What follows is an investigation into the circumstances of Samuel's death and an unsettling journey into the depths of Sandra and Samuel's conflicted relationship.

A sly, sultry character study from filmmaker Justine Triet, SIBYL follows a psychotherapist (Virginie Efira) who decides to quit her practice and return to writing instead. As Sibyl starts dropping patients, she begins to struggle with excess time and a lack of inspiration--until she gets a call from Margot (Adèle Exarchopoulos), a young actress wrapped up in a dramatic affair with her costar, Igor (Gaspard Ulliel), who happens to be married to the film’s director (Sandra Hüller). Becoming further enmeshed in Margot’s life, Sibyl starts to blur past and present, fiction with reality, and the personal with the professional as she begins to use Margot’s life as source material for her novel.

Thomas, a mown and single young painter, urges his best friend to organize a party at home. This evening there, perched on her high heels, Laetitia and her bold catches the eye to him. Together, they cross this night, between frivolously and dramas.