The basic plot involves a corrupt banker named Favraux, who is the target of Judex's revenge.

It is eventually revealed that Judex's real identity is Jacques de Trémeuse, a man trying to avenge his family ruined by Favraux.

Complicating matters is Favraux's beautiful and innocent daughter Jacqueline, with whom the avenger has fallen in love.

A final element comes in the form of Diana Monti and her criminal gang who are working at cross purposes with Judex.

Judex, by contrast, was a heroic persona, but one who had all of the sinister trappings of the flamboyant villains who were popular at the time.