In this chapter, the narrative centers on an unexpected encounter between the three musketeers and Cardinal Richelieu. While patrolling near La Rochelle, the musketeers are intercepted by the Cardinal, who acknowledges them as "brave, loyal, and trustworthy." Despite their political differences, he recruits them for a secret mission, seeking their protection as he prepares to meet with his covert operative, Milady. The musketeers, sensing a deeper intrigue, orchestrate a clandestine surveillance operation. Using an "old stove" and its pipe as a listening device, they eavesdrop on the Cardinal’s meeting in the room above.
Through the stovepipe, Athos and his friends uncover the extent of the Cardinal’s machinations. The Cardinal instructs Milady to travel to London to manipulate the Duke of Buckingham. He demands she convince the Duke to surrender at La Rochelle, threatening, "I will ruin the Queen if he doesn't." The dialogue reveals the Cardinal’s ruthless nature, as he suggests that if the Duke remains defiant, Milady should see to it that he is "injured and unable to continue his plans of attack."
Milady, however, has her own agenda. She seeks the Cardinal’s assistance in settling personal vendettas, specifically targeting Constance Bonacieux and the "scoundrel d'Artagnan." The Cardinal, eager to utilize her as an instrument of his will, agrees to provide her with a note—an "official pardon"—that grants her the authority to seek revenge, effectively arming her against the musketeers' comrade.
Once the Cardinal departs, the tension shifts from political espionage to a haunting personal reckoning. Athos, having signaled his friends to leave, returns to the inn to confront Milady. The revelation is chilling; as Athos reveals his face, Milady recoils, "terrified, as if she had seen a ghost." It becomes clear that they share a dark, shared history, with Athos remarking, "You thought I was dead, didn't you?"
Athos’s intervention is both a warning and a power play. He demonstrates his complete knowledge of her "plotting with the Cardinal," specifically regarding her intent to harm D'Artagnan. He threatens to expose her past as an "escaped thief" to both the Cardinal and the King if his friend is harmed.
In a decisive move, Athos seizes the Cardinal’s letter of protection from Milady. Upon reading the text—which excuses the holder of "any crimes"—Athos realizes the magnitude of the power she wielded. By confiscating this document, he effectively neutralizes her protection. The chapter concludes with a cold, final farewell: "I expect you to leave this country forever. Goodbye, my old love. I pray we never meet again." This confrontation not only protects D'Artagnan but forces a long-buried secret into the light, leaving the reader to contemplate the volatile intersection of statecraft and personal vengeance.