Season 1 begins with a beautiful young woman found dead at the public dump, her face beaten to a pulp by her killer. Leading the investigation, Pierre Clement, young recently-named public prosecutor, teams up with Police Captain Laure Berthaud and examining magistrate Judge Roban. They try to solve the horrendous crime before them: a muddy affair, combining prostitution, drugs, business, and politics.

Originally broadcast as the first season of the television series Engrenages in 2005-2006.