Chapter One—Chapter Twenty-One
This stage takes up just about the first half of the novel. We are distracted by other adversaries—the Man from Meung, Cardinal Richelieu. In Chapter One, our first encounter with Milady is when the Man from Meung relays instructions from the Cardinal. In Chapter Twenty-One, her connection to the Cardinal becomes more explicit as it’s revealed she is the agent who cut the diamond studs.
These are all vaguely ominous evil glimmerings that become more apparent only when D’Artagnan tries to get information from her about Constance.
Although he tells Athos that he’s really just wooing Milady in order to get information on his true love Constance, in Chapter Thirty-One D’Artagnan is clearly falling in love with Milady. Even though he realizes her monstrosity in Chapter Thirty-Two by eavesdropping on her conversation with Kitty, he still can’t help feeling a deep attraction to her.
Later, overcome with his feelings for her, D’Artagnan confesses the trick he played on her, convinced that love will conquer the day. He’s proven wrong when she comes back at him with a dagger instead of open arms.
By now, the full extent of Milady’s evil nature has been exposed. We know that she is a branded criminal, that she broke Athos’s heart, that she tried to kill D’Artagnan (once with a dagger, once with hired assassins, and once with poisoned wine), and that she is charged with facilitating the assassination of the Duke of Buckingham. Her evil power is incredible and seems almost unstoppable.
The side of Good prevails momentarily as she is locked up in what seems to be a completely secure jail. She manages, however to destroy her jailer by convincing him to free her and assassinate the Duke of Buckingham. She gets off scot-free; this incredible turn of events displays the full extent of her power.
Milady has still one more evil act to accomplish—the fatal poisoning of D’Artagnan’s true love Constance Bonacieux. Not only does she successfully befriend and then poison the woman, she does so scant minutes before Constance would have been saved by D’Artagnan and his friends. This is the final ordeal, however, before the destruction of Milady is accomplished.
Death of the Monster
Lord de Winter, Athos, D’Artagnan, Aramis, Porthos, and an unnamed executioner manage to corner Milady, restrain her, try her for all her myriad of crimes, and execute her on a riverbank. Even at this critical juncture, her power and beauty still hold some sway, as D’Artagnan is clearly affected by vestiges of his love for her.
Her position as the novel’s truly evil antagonist is cemented when Cardinal Richelieu, upon hearing of her death, feels "something like a secret joy at being forever relieved of this dangerous accomplice." Her evil portrayed as much worse and far more dangerous than any machinations produced by the Cardinal, and when even he’s glad she’s dead, this is truly the death of a monster.