Mélanie Prouvost, a ten-year-old butcher's daughter, is a gifted pianist. That is why she and her parents decide that she sit for the Conservatory entrance exam. Although Mélanie is very likely to be admitted, she unfortunately gets distracted by the president of the jury's offhand attitude and she fails. Ten years later, Mélanie becomes her page turner, waiting patiently for her revenge.

At the end of WWII, the General De Gaulle decides dissolve all the French resistance networks that helped the allies. Only one was spared, the "304". Kept alive until today, it's mission hasn't change: fight the inside enemy. In 2018, this enemy is called corruption, lobbies and crooked politicians.

Normandy, 1905. The picnic is finished. A group of middle-class people in their Sunday best, get ready to go home. There is one last photo to be taken, but somebody is missing