How Louis XV, a young king loved by his people, sensitive to the artistic and intellectual turmoil of his century (that of the Enlightenment), will end his reign in decay and hatred? Only fifteen years after his death, it's the Revolution.

After eight years of close collaboration with her supervisor, Mathilde suddenly finds herself inexplicably victim of moral harassment by him. In parallel, Thibault has just split up with his girlfriend after a frustrating two-year relationship where they exchanged very little. Mathilde and Thibault have never met, they are just two figures among millions of others. Two people who may bump into each other or who may merely pass each other by. But one day in September, their paths meet.