To atone for his manifold crimes, corrupt banker Favraux (Vitold) is blackmailed by a mysterious figure known only as Judex (Pollock). When he refuses to cooperate, Judex kidnaps him, imprisoning him beneath a ruined castle. He decides not to kill him due to the noble actions of Favraux's daughter, Jacqueline (Scob). But Jacqueline is then abducted by the evil Diana (Berge) who wants to abscond with Favraux's illicit fortune. Judex and his band of shadowy associates pursue Diana, who ensnares the men in a labryinthine game of cat and mouse. Will the noble Judex prevail?

Condensing and reimagining Louis Feuillade's 1914 serial of the same name, Franju pays eloquent homage to silent film, using inter-titles and fades to black to tell his story of a caped crusader out for justice. Judex, with his black hat an cloak, evokes classic figures like Zorro or The Shadow, but remains an opaque character defined mostly by his deft slight of hand (he was played by American conjurer Pollock). Even more vivid is Berge as the feline femme fatale, who slinks about the screen in a black cat suit or else masquerades as a nun. Lyrical imagery (particularly the opening masked ball scene) and an evocative mise en scene add eerie ambience to this iconic, pulpy fairytale.