Paula needs help to prove that her brother is not chargeable, being declared insane, so  to avoid him going to prison. When Pablo meets Paula’s brother,  he concludes that not only he is not chargeable - and any psychologist could prove it –  but also that he wouldn’t be physically capable to  commit such a crime. So, who is the murderer? Obsessed to know the truth, Rouviot reassembles a sinister plot where nothing is as it seems. Doctors, police, lawyers and lovers conspire  in an obscure image alongside a family story  full of violence and obscure points. The question remains till the end of the story, to be revealed by the psychoanalyst, inevitable mix between Sigmund Freud and Sherlock Holmes : Who killed Robert Vanussi ? And why ?