In Marseilles, the discredited and alcoholic Detective Schneider hijacks a bus and forces the bus driver with a gun to drive him home. He is arrested by the swat force and his washed up career in the police department practically ends. Schneider is removed from the investigation of a serial-killer that is committing hideous crimes against women and assigned to a bureaucratic work in the night-shift in the precinct. Through glimpses from his recollections, Schneider recalls the tragic accident that killed his daughter and left his wife attached to a life support system. Meanwhile, the sick criminal Charles Subra, who killed the parents of two girls many years ago, convinces the probation committee in the prison that he has found God and is regenerated and may be released. Justine, one of the daughters that survived, has never overcome the trauma of her loss and is worried with the possibility of the freedom of the criminal. Inspired by true events. In fact when the director was a police officer, this crime was described in the movie happened (parents dead, 2 little girls alive). When these 2 girls were adult, he talked to them about making the movie. And when the movie was finished, he showed them MR 73, they all cried.