We return to the fate of Monsieur Bonacieux, who has been taken to prison and questioned by the authorities about his wife. As it turns out, Bonacieux is much more concerned about his own avarice and safety than he is about his wife. He explains that his only interest in d'Artagnan was that he needed someone who could help him find his wife. When Athos is brought in, Bonacieux tells them that this man is not d'Artagnan. Bonacieux is then taken from the prison, placed in a carriage, and taken for a trip which he assumes is a ride to the gallows.
Later, Bonacieux is questioned by someone whom he discovers to be the powerful and imminent Cardinal Richelieu. While interrogating Bonacieux, the cardinal discovers that the houses which Bonacieux visited with his wife — houses which Constance Bonacieux had said were merchants' houses — are, in reality, the two houses where the duke of Buckingham and the queen's trusted friend, Madame de Chevreuse, have been hiding. When the cardinal calls in Count de Rochefort, Bonacieux immediately cries out that Rochefort is the man who abducted Constance.
Rochefort reports that the cardinal's spy in the queen's inner circle, Madame de Lannoy, has reported that the queen left her ladies-in-waiting and was gone for awhile. When she returned, she was carrying a rosewood box containing the diamond tags which the king gave her. She went into the antechamber and when she returned, she was empty-handed. The cardinal is certain that the duke of Buckingham has the coveted box and the diamond tags.
When Bonacieux is recalled and questioned further by the cardinal, the old man becomes putty in the hands of the honey-tongued cardinal; Bonacieux pledges everlasting loyalty to him. The cardinal then sends one of his men with a letter to be delivered to a woman in England, a certain Milady, who is to dance with Buckingham and secretly snip off two of the diamond tags that he will be wearing.
