A commemorative event in Meaux turns into a tragedy with the death of the president of the organizing association. The authorities entrust the investigation to Lieutenant Karine Lelièvre, to whom Captain Isabelle Guercher is added. The two women are sworn enemies and navigate between their differences and the demands of the investigation. Their research gradually leads them to a disconcerting discovery: the murder turns out to be intimately linked to their shared history. This revelation forces them to reconsider their past and their mutual animosity. (thetvdb.com)