Jean Carne serves as the chief of police for the Shanghai French Concession, a position of considerable authority within the international settlement. His background is defined by ruthless ambition, as he secured his role by murdering his predecessor, Gitendhal, who had been a supporter of the opposing Qīng Bāng. This act reveals a willingness to use lethal violence for personal advancement, driven by a motivation to consolidate power and forge illicit alliances. Carne aligns himself closely with the Hóng Huá Huì, a powerful Chinese secret society, acting as a corrupt official who protects their interests in exchange for his position.

Within the story, Carne functions as an antagonist representing the decayed and self-serving side of authority in 1930s Shanghai. His most significant relationship is with Charles de Guise, another French figure in the city, who ultimately convinces him to abandon his post. After his ally Pān Guāng-Lín is saved from a critical situation by the protagonist Kenshirō Kasumi, Carne’s corrupt dealings become a liability, shaming the French government. Following de Guise's advice, he attempts to flee to South America using a forged passport. His development takes a fatal turn at this juncture, as he does not escape. Instead, Jean Carne is shot to death by Pān Guāng-Lín, the very person whose rescue precipitated his downfall. Regarding his methods or fighting prowess, no information is available.