Marianne Winckler (Juliette Binoche) is actually more likely to wield a pen than a broom. For the research for her new book on precarious working conditions, the renowned Parisian writer wants to experience the reality of the low-wage sector first-hand. “To make the invisible visible” - as she says at one point. Marianne pretends to be a recently abandoned, penniless wife, finds work as a cleaner in Normandy and discovers a life that is ignored by the rest of society and in which every euro earned counts. Cleaning the ferries under time pressure is a tough experience. On the other hand Marianne experiences solidarity and a strong bond with her new colleagues. The mutual help and support leads to friendship and trust. But what happens to this trust when Marianne's original intentions come to light?