For the arch-criminal Fantômas, no crime is too daring, too adventurous. A master of disguise, he has no trouble relieving the Princess Danidoff of her priceless pearl necklace at the Royal Palace Hotel. Inspectator Juve is determined to capture Fantômas and put an end to his limitless villainy. Whilst investigating the disappearance of Lord Beltham, Juve finds himself on the trail of his arch-enemy once more. He discovers that Beltham’s widow has been having a secret affair with a mysterious stranger, Gurn. In Gurn’s apartment, Juve discovers the dead body of Lord Beltham and business cards bearing the name Fantômas. A triumphant Juve makes an easy arrest of Gurn, alias Fantômas, and is sure that nothing can save the evil-doer from the guillotine. But Lady Beltham has an ingenious plan to save her lover, using an actor Valgrand who closely resembles Gurn.