Marianne Winckler (Juliette Binoche), a well-known author, goes to live in northern France to research for her new book on the subject of job insecurity. Without revealing her true identity, she gets hired as a cleaner, working with a group of other women. In this new role, she experiences financial instability and social invisibility first-hand. But she also discovers mutual assistance and solidarity, strong bonds shared by these behind-the-scenes working women. Based on French journalist Florence Aubenas's bestselling non-fiction work Le Quai de Ouistreham.