Christmas night in Roubaix. Police chief Daoud roams the city in which he grew up. Burned-out cars, altercations. At the station, Louis Coterelle is the new arrival, fresh out of the academy. Daoud and Louis will be confronted with the murder of an old woman. Two young women are questioned. Claude and Marie - destitute, alcoholic, lovers. Competing in the 2019 Cannes Film Festival for the Palme d'Or, Oh Mercy! is the latest film from Arnaud Desplechin (Ismael's Ghosts), a true-crime film offering a dark, yet compassionate, exposé of the flawed human condition.