The fearless Inspector Juve, aided by his sidekick Fandor the journalist, gets drawn into the Paris underworld by a series of mysterious crimes committed by a criminal gang that he believes is headed by Fantômas, believed to be dead by the rest of France. As he pursues the disparate clues and desperate characters involved, he finds himself again drawn into the orbit of his arch nemesis, the fiendish, shape-shifting Fantômas.