As a student cinematographer at a film school, Cédric is faced with some major problems.

This documentary by director Claire Billet and historian Christophe Lafaye details the massive and systematic use of chemical weapons during the Algerian War. Algerian fighters and civilians, sheltering in caves, were gassed by "special weapons sections" of the French army. The gas identified on military documents is CN2D, whose widespread use forced insurgents to flee "treated" sites, at the risk of dying there. The method is reminiscent of the "enfumades" used by the French expeditionary force during the conquest of Algeria in the 19th century. Between 8,000 and 10,000 such operations are believed to have taken place on Algerian soil between 1956 and 1962. This historical aspect is little known due to the difficulty of accessing archives, many of which are still classified, raising questions about memory, historical truth, and justice.