Voulant prouver la valeur de son arbre généalogique, Monsieur Barbezieux de Saint-Rosay attend la visite d'un cousin qui détient, paraît-il, les titres de noblesse de la famille. Il assiste alors à un défilé d'individus plus ou moins respectables, plus ou moins saugrenus, qui se présentent comme étant ledit cousin. Celui-ci remet un peu d'ordre à la fin dans la famille de Saint-Rosay.

For the Marquis Barbezieux de Saint-Rosay, nobility is important. If anything can comfort her, it's her family tree. In order to erase any doubt he invites in his castle a cousin of his established in Scotland, whom he instructs to bring him his titles of nobility. A first person introduces himself, calling himself his cousin, but it's not him. Then one, then two, then three false cousins ​​appear in turn. Will the real Saint-Rosay of Scotland eventually present itself?