The homeless Charles, aka The Dirty, is the witness of Alexandra's murder during a black mass. Discovered by the murderers he runs away and in the morning later goes to the police station. The young and intolerant superintendent Megretti discredits the homeless person as a mythomaniac and knocks him outside the office. Therefore The Dirty goes to the private detective Teo Marchesi, aka The Filthy. Teo Marchesi has a small and dirty investigation agency that manages with his idiot assistant, Humprey. Obviously The Filthy refuses the case because of the fact that The Dirty can't pay the investigation. So the homeless at the end goes back to do his poor outcast's life unconscious that the killers are already searching for him. When Alexandra's murder finally jumps to the chronicle honours only a stolen wallet and a full of money mattress will push up the investigations. Protagonists' lives will change for ever, taking them towards a daring and unforeseeable conclusion.