Princess Sonia Danidoff is staying at the Royal Palace Hotel, Paris, and withdraws $20,000 from the cashier's custody, placing the notes in a drawer in company with her magnificent rope of pearls. A few moments after a well-dressed stranger steps from behind the curtains and, with the coolest of sangfroid, steals the valuables in the very presence of the princess, and with a polite bow hands her his card and makes a dignified exit. Upon the card the name "Fantomas" slowly appears. The police are quickly upon the scene, but Fantomas, true to his nom de plume, has vanished. Inspector Robert Juve is the sleuth entrusted to track the mysterious marauder. But before Juve has time to move in the matter of the princess's jewels and cash, another escapade of Fantomas' is thrust upon him to investigate. Lord Beltham is missing. Juve calls on Lady Beltham, and in a man's hat finds the initial "G." With so slight a clue Juve tracks down "Gurn" (none other than the elusive Fantomas) to his lodgings and makes the ghastly discovery of Lord Beltham's dead body in one of "Gurn's" traveling trunks, and a packet of the special Fantomas cards establishes the connection between "Gurn" and Fantomas; they are one and the same man. Three months elapse. "Gurn" has been tried and condemned to die by the guillotine. Lady Beltham's name has not yet appeared in connection with the case, and the story goes that the murder was the outcome of a violent quarrel between "Gurn" and Beltham, yet she is enamored of the gentlemanly scoundrel and sets about seeking a method of escape for him. By means of liberal bribes, the aid of Warden Nibet is enlisted and he arranges an interview between the condemned man and Lady Beltham in a house overlooking the prison. That night a new play has been produced by a famous actor, Valgrand, who, acting the role of a condemned felon, adds a realistic touch by making up exactly to resemble "Gurn." At Lady Beltham's invitation, Valgrand, still made up as "Gurn," visits her at 2 A.M., and partaking of drugged coffee, is rendered incapable of action. Warden Nibet returns and takes back his prisoner, no longer "Gurn," alias Fantomas, but the unfortunate Valgrand, who goes through all the terrible preliminaries of a criminal's execution, aye, even to the point of being led to the guillotine, before inspector Juve makes the startling discovery that Fantomas has once more eluded him. Henceforth it is to be a fight between a clever, scheming, mysterious rogue on one hand, and inspector Juve, Chief of the Detective Dept. of Paris, on the other.