Inspector Truchaud is now back working in Paris, nursing a bruised if not broken heart after the delicious Nathalie has announced to him that she is going to have a baby with his colleague and rival, Inspector Lucas. When Lucas' body is found, murdered, on the stage of the Loreley Theatre in Germany's Rhineland, Truchaud is sent to liaise with the German police over the murder. What nobody realises until Truchaud arrives is that Lucas was traveling with the heavily pregnant Nathalie, who has now disappeared. Truchaud sets out on a quest to find out what has happened to her, and, if possible, rescue her and her unborn child.