The series reaches its thrilling climax as an unexpected rift between the Musketeers threatens to blow them apart. Athos takes a woman hostage in the square, and the Musketeers are amazed to discover he is threatening none other than Milady. Athos is furious when he finds out that D'Artagnan knows her, testing their friendship to its limits. D'Artagnan is forced to do the unthinkable and seeks Milady's help.