Danceny replies (Letter One Hundred and Fifty-seven) gallantly to say that he will fly to his Cécile's side.
Valmont then composes another missive to Merteuil (Letter One Hundred and Fifty- eight), in which he mocks her for getting stood up by Danceny. Merteuil sends Valmont a court note in reply (Letter One Hundred and Fifty-nine), stating her annoyance with such cheap tricks.
Again, Madame Volanges writes Rosemonde (Letter One Hundred and Sixty) this time to send along a mysterious letter Tourvel dictated to her maid. The Présidente lost consciousness before the envelope could be addressed, but one can guess for whom the letter is intended. The letter itself (Letter One Hundred and Sixty-one) is addressed at first to a cruel and malignant man, but moves on to direct itself toward a wronged husband, and then returns to the evil lover again.
It seems that Merteuil has been active on the warfront. Danceny writes to Valmont (Letter One Hundred and Sixty-two) to summon him to a duel for the wrongs he has committed. The next letter (Letter One Hundred and Sixty-three) is proof that Danceny has carried out his duty: it is a report to Madame de Rosemonde that Valmont is dead, run through on Danceny's sword. Before he died, however, Valmont managed to hand over a collection of papers, which one can only assume are his damning letters from Merteuil. Letter One Hundred and Sixty-four is a request from Madame de Rosemonde that Danceny be prosecuted for her nephew's murder.
Finally, the word "danger" is put down on paper. In Letter One Hundred and Fifty, Danceny writes to the Marquise de Merteuil, We are to deny ourselves a correspondence which, according to you, is dangerous and for which there is no necessity (...et nous nous priverons d'un commerce qui, selon toi, est dangereux, et dont nous n'avons pas besoin).
Either a theme of danger has finally been introduced to the novel, or it has only now surfaced even though it was present all along. However, Danceny's change of heart seems more dangerous than his actions. As readers, we feel endangered by Danceny's changeableness. Was he not a moment ago the one character in the novel whose feelings and intentions were devoted to a single other person alone? Was he not truly and unswervingly in love with Cécile?