Things quickly go wrong. An arrested boy tries to commit suicide in the police station. His father gets very angry but the family is so bizarre that Kreusky and her team decide to dig deeper. The drug deal in the Cité has brought the narcotics at the Police station. This cohabitation is hard to cope with for everybody except for the pretty lieutenant who has a crush for a narcotic lieutenant.

It's Christmas Eve. The Christmas tree is in the cafeteria, everything's fine. Except that an ordinary man decides to burglar a small jewellery. He takes the saleswoman as a hostage. A school teacher fails at taking care of her own son and she accuses her sister to lock her up.