Middle-aged musician Antoine suddenly decides to end his career. After several days aimless wandering, he is hired as the caretaker of an old residential building in Paris. Mathilde is a recently retired resident, generous-spirited and deeply involved with the management of the building. After she discovers a crack in her living room wall, her worry gradually turns to panic - what if the building were to collapse? Slowly, Antoine develops a fondness for this woman he is afraid will slip into madness.