This time, the actor plays a more resilient and less taciturn character, Laurent Amédéo, an employee in the Perrin factory. Management has decided to shut down all operations at the site in spite of the onerous financial sacrifices employees have made and the company's record profits. After a flouted agreement and broken promises, Laurent Amédéo becomes the union spokesperson for 1,100 employees who refuse to accept this decision. Together, they fight a battle to save their jobs.

Stéphane Brizé has called on non-professional actors to play opposite Vincent Lindon. "The veracity of their life experience lets me create a representation of reality that I find very moving", says the socially engaged director. To produce a naturalistic treatment of the reality of social issues involving a clash between people, Stéphane Brizé has chosen as director of photography Eric Dumont, who has made his mark in documentary films and with whom Stéphane Brizé has worked previously on La Loi du Marché (The Measure of a Man).

Filmed in just 23 days, En Guerre (At War) presents the opposition between two points of view, the human dimension and the economic dimension. Through this contrast, Stéphane Brizé examines social and political dysfunctions in the 21st century in a reassessment that he had already broached in La Loi du Marché (The Measure of a Man).