An important slot machine salesman has been kidnapped. The police suspect Valérie, his partner, of having organised the kidnapping. Already well-known to the police, her lies only serve to make them even more suspicious.

Lulu works on the black as a security officer in a gay restaurant. One evening, the premises are attacked by masked men who steal his police weapon. To save his colleague's career, it's imperative that Franklin finds those who carried out the assault.

Germain Vidal is arrested as he prepares to throw his partner's body into the Seine. At the same time, the police officers are investigating the suicide of Natacha Valmorel, mistress of a leading light in the world of the press.

It's Christmas Day in the evening but the team is feeling anything but festive. One of the day shift committed suicide in the toilets. Each tries to piece together the circumstances that led to the tragedy. Meanwhile, Franklin is in search of Le Solitaire, known for stealing from elderly women...

A jeweller is detained by force in his shop and his family held hostage. The police manage to arrest two of the criminals with no harm done. But the third forces his way out and takes Anne hostage...