Hadjis, a professor of thirty-year-old philosophy, implemented his spiritual concepts by abandoning Europe to settle in a popular district of Tunis and live in destitution. With two followers of his philosophy, a medical student and a poet, they form a well-knit together. Unfortunately, while he is one day under the effect of lack of hashish, Hadjis strangles a prostitute. The police entrust the investigation to an officer who is quick to find the track of the criminal. But, converted by the three friends to their philosophy, he ends his investigation and leaves the police to join them.