D’Artagnan immediately insults Monsieur Bonacieux and tells Madame Bonacieux that her husband is not trustworthy. In sharp contrast, d’Artagnan is prepared to do whatever she needs. Madame Bonacieux believes d’Artagnan and decides to tell him about the queen’s predicament. As she does, she realizes she is falling in love with d’Artagnan. D’Artagnan agrees to the job, though he’ll need to make sure that M. de Tréville will give him the proper time off. He also requests funding. Luckily, that turns out to be no problem; Madame Bonacieux gives d’Artagnan the pistoles that the cardinal presented to her husband. D’Artagnan is delighted and once again declares his love for Madame Bonacieux.
D’Artagnan does not mince words when talking about Monsieur Bonacieux because he has so little respect for him. Of course, it doesn’t help that Monsieur Bonacieux is married to the woman he loves. Luckily, d’Artagnan gets the chance to prove his love to Madame Bonacieux and embark on his first real adventure. D’Artagnan believes that if his mission is successful, it is likely that Madame Bonacieux will fall in love with him.
Outside, Madame Bonacieux hears her husband talking to someone and realizes that they need to hide. D’Artagnan suggests that they use his apartment. As they head upstairs, d’Artagnan sees that the man Monsieur Bonacieux is talking to is Rochefort, though d’Artagnan doesn’t yet know his name. D’Artagnan thinks about attacking Rochefort on the spot, but Madame Bonacieux insists that they hide upstairs instead. Once they are upstairs, d’Artagnan shows her the hole he’s made in his floor that allows him to hear whatever goes on down below. Together, the two of them listen to the conversation between Rochefort and Monsieur Bonacieux.
Although the reader now knows the name Rochefort, d’Artagnan is still in the dark. He only knows him as “the man from Meung.” As usual, just the sight of Rochefort angers d’Artagnan, but Madame Bonacieux’s good sense prevails and the two of them hide upstairs instead of facing Rochefort head on.
Rochefort asks Monsieur Bonacieux if his wife knows that he is acting as a spy. Monsieur Bonacieux assures him that she does not. Rochefort also asks him where his wife is now, and he tells him that she is at the Louvre. This seems to satisfy Rochefort, but he is angry that Monsieur Bonacieux didn’t just accept his wife’s mission and immediately turn over the letter. Monsieur Bonacieux tells him that he can just go to the Louvre and tell his wife that he will take on the mission. This angers Madame Bonacieux, who curses at her husband. D’Artagnan urges her to be quiet so that they are not caught spying. After Rochefort leaves, Monsieur Bonacieux realizes that his money is missing, and he starts screaming bloody murder. This amuses Madame Bonacieux and d’Artagnan.
This scene is filled with irony as Monsieur Bonacieux once again demonstrates his utter ignorance. Meanwhile, Madame Bonacieux now knows for sure that her husband betrayed her. This is a bad sign for their marriage, but a good sign for d’Artagnan, who is hoping she will fall in love with him. Monsieur Bonacieux’s betrayal means that d'Artagnan must be the mature one for once to make sure that Madame Bonacieux doesn’t give them away out of anger. The chapter ends on a satisfying note as Monsieur Bonacieux is symbolically punished for his betrayal because Madame Bonacieux stole his money and gave it to d'Artagnan.