The play takes up several elements from Madame d’Aulnoy’s story Le Nain jaune (The Yellow Dwarf, 1698), particularly the motif of the princess endangered by the proposal of a diabolical suitor. But it simplifies and largely modifies the plot, notably by replacing the King of the gold mines by the young Yvon and by adding a happy ending.

In the cast of Yvon, ou la Barbe d’Acier, the names of the characters figure alongside those of the puppets playing them. Thus, Yvon, the main character, is played by “Belle Rose” (Beautiful Rose), which was the by-name of the hero in Amédée Achard’s Les Conquêtes de Belle-Rose (1847) – a popular swashbuckling novel. The houseboy is played by Jacques, Fleur de Bois by Blondine, and the King Mygonais by Barbe Grise. This kind of cast is typical of the outlines of the Théâtre de Budt’s plays.

The Nain jaune (yellow dwarf) wants to marry Fleur de Bois, a princess, but she turns him down. To avenge himself, the Nain, with the help of Satan, puts the king, the princess and everyone in the palace to sleep, and he promises to come back in a year. Yvon, a young man described as “not very rich but lazy”, begs a Prêtre (Priest) for money. The Prêtre turns into a genie and gives him an enchanted sword so he can save the princess. He and his servant fight the Nain, the Géant Romular (Giant Romular) and Satan, and enter the castle. Once inside the castle, Yvon cuts the king’s beard with the sword to deliver him from the sleeping spell. When the king wakes up, he gives Yvon his daughter Fleur de Bois as a wife.