Marcel, rich and alone for Christmas, invite Françoise to celebrate with him. Soon, the fairy tale turns into a bad dream.

Count Hubert de Latour Latour is the lover of the Duchess de Maulévrier. The day he is surprised by the Duke in the company of his wife and... in a rather compromising situation, Hubert resorts to a subterfuge, claiming that he has come to see the Duchess to seek support to be elected at the Institut de France, whose chairman is precisely her husband. The latter takes him at his word and Hubert becomes... a member of the French Academy! Which just shows that everything leads to everything.

Louis Mennechain is a modest locksmith. So imagine his amazement when Professor Piétrefond approaches him and tells him he recognizes in him a descendant of the kings of France, more precisely of Louis XVII (the king who never reigned). According to him he is none other than the monarch's great grandson. Louis's life is soon turned upside down as he becomes the center of attention of a group of ardent royalists. Even a duchess "gives" him her love to make sure that he accepts his role as pretender to the throne...