Was initially planned to be split in two parts, lasting 90 minutes each.
Was exceptionally allowed to film a scene at the 36 Quai des Orfèvres in Paris, the city's Police headquarters from 1913 to 2017. This is thanks to Martine Monteil, author of the book the film is based on and its main character, who was the first female chief of Paris' drug squad, vice squad, organized crime squad, crime squad and judicial police.