Antoine is a musician. The forties, he suddenly decides to end his career. After a few days of wandering, he gets a job as a janitor. Mathilde lives in the old building in the east of Paris where he takes office. This is a young retiree, generous and involved, who divides his time between his associational activities and the life of the condominium. One night, she discovers a disturbing crack on the wall of his living room. Gradually, his anxiety grew to turn into panic and if the building collapsed … Slowly, Antoine befriends the woman he feared to see slip into madness. Between slips and concerns, both form an awkward tandem, humorous and solidarity which will, perhaps, through this bad patch.