Journalist Helena Folasado, of course, had to say “no” when a stranger in a cafe asked if she was waiting for Monsieur Bellivier. But creative stagnation and a natural adventurous streak made her say yes. So she got a highly paid and very strange job, which evokes a feeling of involvement in a mystery. A native of Tunisia, Mancebo, the owner of a small shop in the vicinity of Montmartre, leads a measured life. But one day a neighbor from the house across the street approaches him and offers to follow her unfaithful husband. To his surprise, Mancebo agrees. Helena and Mancebo have never met before, but their missions will intersect in the most surprising way. And as soon as this happens, it will become clear that the cafes and streets of Paris keep much more secrets than one might expect...