Turin, Italy: France flight attendant Linda and Italian-American detective Enzo Avolfi team up to find Linda's younger sister Celine. Celine, a model, has been abducted by a serial killer. Known only as "Yellow" ("Giallo" in Italian) he kidnaps beautiful foreign women in his unlicensed taxi cab. After drugging them, the killer proceeds to mutilate and finally murder them. He photographs his deeds so that the photos may grant him personal sexual gratification.