In Lille’s police department, the case of Antoine Levasseur’s murder is almost solved. But when the case file falls into the hands of the building’s highly intelligent cleaning lady, Morgan, all facts are called into question.

The police investigates the case of a man who was found drowned in his hotel room bathtub. In the meantime, Morgane accepts the position of police consultant, but sets one very specific term for her collaboration.

When two little girls disappear, everyone’s suspicions turn to their father, a solitary and unstable man. Everyone’s except for Morgane’s. Meanwhile, a new lead regarding Romain’s disappearance comes to light.

A vet is found dead in her clinic and, although it is initially believed that she died of natural causes, Morgane discovers that she was actually poisoned. Meanwhile, Morgane meets her mother to learn more about Romain.

With Romain’s death now confirmed, Morgane is once again stricken with grief. Meanwhile, a man is taken to the hospital in a state of coma, after a murder attempt against him. But what could have been the motive?

A Lille football club supporter is found dead in the court’s changing rooms. Accompanied by her daughter, Thea, who is doing an internship at the police, Morgane sets out to investigate the male-dominated world of football fans.

When the dead body of a kite-surf club manager is found on a beach, all suspicions fall on the sole eye-witness of the murder. But Morgane believes he is innocent and will do everything in her power to prove it.