The three men don’t know the identity of the woman they protected that night, but it’s clear that she is an ally of the Cardinal.
Porthos calls for some dice.
Aramis and Porthos begin to play as Athos paces around the room thinking.
Several times, he passes a stovepipe and hears voices.
Athos gestures for his friends to be quiet, and the three of them crowd around the pipe to listen.
The Cardinal is talking to Milady: he orders to find Buckingham in England and instruct him to cease and desist. Buckingham must stop his war preparations or else the Cardinal will ruin the Queen.
The Cardinal outlines everything he knows about the Duke’s movements that could compromise the Queen’s honor.
Milady memorizes the list of accusations, and then asks what should happen if the Duke persists in continuing his war.
The Cardinal says that is highly unlikely, but if the Duke does persist, he would hope "for one of those events which change the destinies of states."
(This means that he hopes for an assassination.) He suggests that Milady find one of the Duke’s enemies to stab the Duke to death.
Milady, worried that she would be named as an accomplice, asks the Cardinal for a carte blanche, that is, an order deeming that all her actions are beneficial to France.
She recites all the evidence that the Cardinal has against the Queen and Buckingham. Satisfied that she will carry out the Cardinal’s instructions, Milady then has a list of requests for the Cardinal. She points out that she made a number of enemies while serving him, the first being Madame Bonacieux.
Milady wants to know which where Madame Boancieux is located. The Cardinal promises to find out.
Next, Milady vents about D’Artagnan. The Cardinal demands proof of his connection with Buckingham before arresting him. Milady promises to deliver that proof.
While the Cardinal signs the carte blanche, Athos draws his friends to the other side of the room and tells them he has to leave. Porthos and Aramis are to tell the Cardinal that the roads are unsafe and that Athos has gone on the lookout.
Athos instructs the esquire to tell the Cardinal the same story, and then departs on the road back to camp.