Something is wrong with the saline deposits in Guérande: Therefore, the journalist Lilou who investigates in that case contacts her friend inspector Dupin and asks for an urgent meeting. They agree to meet at the suspicious place, where according to Lilou's findings there is massive environment danger caused by the company producing the salt. Instead of Lilou, a bullet meets Dupin's arm who just in the last second can escape from the sniper. Lilou has disappeared. The inspector who is responsible for the precinct, Rose, doesn't like to see Dupin investigating the whereabouts of Lilou who finally was found dead. Nevertheless, Dupin and his team who continue their investigations against the will of Rose find out that the reason for Lilou's murder are the dirty methods of the powerful local salt industry.