Hadjis, a philosophy professor in his thirties, put his spiritual concepts into practice when he left Europe to settle in a working-class district of Tunis, where he lived in destitution. Together with two followers of his philosophy, a medical student and a poet, they form a close-knit, wise cenacle. Unfortunately, Hadjis strangles a prostitute while on a hashish binge. The police put an officer in charge of the investigation, and he soon tracked down the murderer. But, converted by the three friends to their philosophy, he ends his investigation and leaves the police to join them.