In spite of this being the second time of reading, and having seen two versions of the film, I still burnt the candle at both ends to finish this.
Tension builds up as two jaded and cynical ex-lovers in eighteenth century France, Valmont and the Marquise de Merteuil, plot and scheme with selfishness and cruelty to seduce others for their gratification or revenge. The Marquise is incensed when Valmont falls in love, in spite of himself, with a virtuous married woman, but by plotting the downfall of her rival the Marquise brings about an ultimate all-round destruction.
Don't be put off by the fact the book consists entirely of letters. It works perfectly, and the psychological depth of each of the characters is astonishing, particularly the understanding Laclos has of the rivalries between and amongst the sexes. I almost pitied Valmont who realised too late the value of what he had lost, and the unworthiness of her he had made the sacrifice for. I kept thinking of these words from Desiderata: "neither be cynical about love, for in the face of all disenchantment, it is as perennial as the grass." Too late, he laments "we are only happy through love."
However I would not particularly recommend this, my 1924 translation and introduction. I am sure it has since been improved.