Un fil à la patte

Monsieur Fernand de Bois-d’Enghien, who has had a long on-off relationship with Lucette, has just returned to her after a few weeks apart. While he acts as though everything is normal, he reveals in asides to the audience that he will marry Viviane, daughter of the esteemed Baroness Duverger. He does not know how he can break the news to Lucette, who loves him to an extreme degree and would surely be completely devastated if he left her. As the morning continues, more characters arrive at the apartment. Bouzin is a notary's clerk who dabbles in song-writing. Although he does not know Lucette, he brings along a song he's written for her.

Although he is sent off after Lucette has dismissed his song to be stupid, she and the guests later discover an anonymous bouquet and ring sent to Lucette. While the gifts had actually been sent anonymously by General Irrigua, a South American minister of war who absolutely loves her, Bouzin had sneakily planted his business card in the bouquet. When he returns for his forgotten umbrella, they surround him welcomingly, soon sending him back to his apartment to retrieve the song while they start planning changes.

Lucette tells him she is in love with someone else, he asks Bois-d'Enghien who her lover is. He realizes the General wants to kill him, so he lies and says the lover is Bouzin. Meanwhile, Lucette is meeting in another room with Baroness Duverger, who is hiring her to sing at the wedding that night.

While preparing for the guests to arrive, Viviane reveals to her mother, the Baroness, that she has a particular fetish for men with scandalous reputations, which she doesn't think Bois-d'Enghien to be. Bois-d'Enghien then arrives, and is shortly followed by de Fontanet, who also ate lunch at Lucette's apartment that morning and doesn't realize Bois-d'Enghien's predicament. He reveals details about Lucette which Bois-d'Enghien is forced to cover for until he can explain his situation to de Fontanet in private. While they are talking, Lucette, her sister Marceline, and de Chenneviette, who is acting as her manager, arrive. Bois-d'Enghien scrambles to hide in a wardrobe while de Fontanet covers for him. Baroness Duverger shows Lucette her dressing room before leaving her alone to get ready for the night. She and Marceline soon find Bois-d'Enghien, who's presence in the wardrobe frightens and confuses them. He says he was playing a joke and pretends he is only a guest at the wedding.

While Bois-d'Enghien is able to tell his story to de Chenneviette, he spends the rest of the night telling numerous lies to hide his story from everyone else. When she comes to, she is furious at Bois-d'Enghien and, while he tries to convince her that he will not be married long, she pulls a trick on him by putting a rose down his back. When he is forced to strip down to remove it, she starts screaming with joy, which brings everyone into the room to find the two of them in their undergarments.

The stage is split between part of Bois-d'Enghien's apartment and the hallway outside it, which connects to the building's main staircase. The act begins with a monologue from Jean, Bois-d'Enghien's valet, who sends off a florist who was looking for a wedding that was in fact taking place on the floor above. Bois-d'Enghien soon arrives, complaining that he had been locked out after losing his key and had to stay in a hotel. He sends Jean out to have a new lock made.

Not long after, Bouzin, who, by chance, had been the notary's clerk at the wedding, arrives at the apartment to deliver a bill and a copy of the contract. Bois-d'Enghien tears up the contract and Bouzin is just about to leave when the General arrives. There is a grand chase scene before Bois-d'Enghien sends the General down the stairs after the wrong person. Bouzin, although unharmed, is too terrified to leave or even answer the door when Lucette comes. However, she lets herself in with the key Bois-d'Enghien had lost. She tries to make up with Bois-d'Enghien but he refuses and tells her that he's through with her. She then leaves, and shortly after the General returns.

Bois-d'Enghien convinces the General he can have Lucette and tells him how to win her, sending him running down the stairs after her. Bouzin, who had been in a back room while Bois-d'Enghien and Lucette talked, then comes out from the apartment but fails to catch the door before it shuts and locks again. Bois-d'Enghien spots the gun and uses it to force Bouzin to give him his trousers and vest. Bouzin is then forced to flee upstairs when the concierge comes up with policemen looking for a man in his underclothes. They continue upstairs as Viviane arrives, to the surprise of Bois-d'Enghien. Having discovered that Bois-d'Enghien does in fact have the scandalous reputation she desires, she has returned to reunite with him. Madame Duverger, who was attending the wedding upstairs, soon discovers them, and gives in to Viviane's pleas for her to be married to Bois-d'Enghien.