A beautiful young woman lies sprawled on her berth in the sleeping car of the night train from Marseilles to Paris. She is not in the embrace of sleep, or even in the arms of one of her many lovers. She is dead. And the unpleasant task of finding her killer is handed to an overworked, crime-weary police detective named Pierre Emile Grazziano, nicknamed Grazzi, who would rather play hide-and-seek with his little son than cat and mouse with a diabolically cunning, savage murderer.