Georges Franju's Judex is an arch, playful tribute to the serials of the influential silent filmmaker Louis Feuillade. Franju shuffles through the plot of Feuillade's lengthy serial of the same name, about an adventurer named Judex whose revenge against the corrupt banker Favraux unleashes a complicated series of schemes.

Jean, nicknamed Brasse-Bouillon, and his brother Ferdinand live with their paternal grandmother, who is responsible for their upbringing. But when their parents returned from Japan, they settled in Belle-Angerie and resumed their role with the children, while their grandmother had to leave for cousins. The boys soon come up against the contempt of their mother, Marthe. Faced with this shrew, whom he nicknamed "Folcoche" (a contraction of "madwoman" and "pig"), Jean decided to join the resistance.