"Jérôme K. Jérôme Bloche" Un chien dans un jeu de quille

A woman offers Jérôme 15,000 euros to kill a man. He refuses and shows her out, but she vanishes without leaving a name or address. Fearing she has already engaged a real hired killer, Jérôme sets out to find her before it's too late. First part of a two-volume story.