Marseilles, 1919. Georges Sarret is a distinguished and respected lawyer, recently honoured for his services in the First World War. He takes as his lover Philomène Schmidt, a young German woman, who has just lost her job and home. To enable Philomène to remain in France, Georges finds her a husband – who dies conveniently of natural causes a month after the wedding. Georges repeats the trick with Philomène's sister, Catherine – marrying her off to an old man who dies suddenly so that the scheming trio can profit from his life insurance. When an accomplice in the scheme, Marcel Chambon, threatens to blackmail them, Georges and his two lovers have no option but to kill him and his mistress...

The story is based on Voltaire's tale "Le monde comme il va" ("The world as it is"). Sent by the genie who presides over the destiny of Persepolis (Paris!), the Scythian Babouc carefully informs himself of everything, to tell the genie whether or not to destroy the city. This is the pretext for a series of interviews, scenes taken on the spot or reconstructed in the studio. We meet a musician who lives for his art and a Marxist historian, both of them optimists in the end; but also a war widow and an economically weak old lady: while the "fureur de vivre" gives free rein to the Golf Drouot and socialites hide their turpitudes behind a façade of good manners. A large, poorly housed family bravely faces up to its fate, and the children are happy; a working-class household talks about the union struggle, inhumane working conditions and reasons for hope. Finally, a poet sums it all up by talking about his commitment to the service of mankind.