It comes as a something of a surprise to Athos, but the discovery that his late, lamented, murdering wife is alive and well and, subsequent investigation reveals, working for bloody Richelieu (and God knows who else; he suspects her of infidelity to her country as much as to her various husbands), is quite liberating. No more the aching feeling of love-lorn guilt, no more the nightmares, no more the grief. Several more dead bodies down the line, he feels entirely justified in the decision he had made when he was merely the naïve Comte de la Fère, intent on maintaining the law in his demesnes. She attempts to seduce, and then murder, D'Artagnan. She kills an envoy from the Spanish Netherlands, and attempts an assassination of the English ambassador – he quite enjoys foiling that one. In fact, he's enjoying his career as a musketeer with far greater relish than he ever has previously, freed as he is from the bonds of the past.
He takes the time to discover more about her. She was no innocent when they met, he finds. Quite likely she planned that meeting herself, every detail carefully plotted, so that in his stupidity he would fall helplessly in love with her, laying himself at her feet (which he did). Every smile, every kiss, every gesture was calculated to enslave him. And he is no longer enslaved.
They cross paths again on the road to Calais, the musketeers on a mission to prevent a conspiracy between the Cardinal and Buckingham. They fight; Athos enjoys it. All the more, he thinks, later, a bottle of wine down, because he was not given the opportunity to kill her. He might have to, one day. She is no friend to France, no friend to the King.
The guilt is mostly gone; he knows the wife he loved for a whore and a murderer and a traitor. But he cannot get the memory of her out of his blood. Deep down, he thinks, she is still his wife. He no longer has nightmares, it is true, but that doesn't mean he doesn't dream of her and is woken with longing.
One night, she comes to him. He wakes, and there she is, sitting on the edge of his bed, in darkness except for the glint of moonlight against the outline of her cheek.
"Come to kill me at last?" he says, sleep rusting his voice. He thinks of the sword lying on the floor a mere arm's length away, but doesn't reach for it.
"A night-time assassination?" she replies, reaching out, lightly touching his hair. "How very tedious. You'll suffer when I kill you, my dear Athos."
"I do not doubt it," he says, and draws her back onto the bed with him.
He makes love to her, and she steals his pistol on the way out. It is very possible, he thinks, dressing the following morning, that she intends to implicate him in some crime. He can't help but smile. One day, Athos will have to kill her. He just hopes he gets there before someone else does it.