Marchioness De Merteuil has a score to settle with Count De Gercourt, and she would love to see him humiliated.  Now is the perfect moment, as he is preparing to get married to Cécile, the daughter of Madame De Volanges, and it would mean a lot to Marchioness De Merteuil if his untouched bride-to-be is not as untouched as he believes.  For that she requires the help of a friend of hers, Viscount Valmont, who has made it his hobby to use and dump women.  But Viscount Valmont has found the ultimate challenge in Madame De Tourvel, who is known for her piety and conjugal fidelity.  She would be the ultimate trophy to complete his already long list.

The young Cécile however fell head over heels for the handsome cavalier Danceny, her music teacher.  At first both try to hide their feelings, but soon they start an intense written conversation of love-letters, one of which is unfortunately intercepted by her mother.  Danceny is no good match for madame De Volanges daughter, and she will make sure the planned wedding with Count De Gercourt goes ahead as planned, so she sends her daughter away from her handsome Danceny, to spend some time at Madame De Rosemonde's place - where Valmont and his target, Madame De Tourvel, stay as well.

The interception of this letter was no coincidence, Marchioness De Merteuil has hinted Madame De Volanges about the romantic afternoons of her daughter.  Not out of philantropy, but as part of her plan, she feared the young Danceny would otherwise be happy just holding hands and that did suit her plans.  And now Valmont and De Merteuil manoevre themselves in the position of secret accomplishes of the two young lovers.  She hopes that this way she'll achieve the disgracement of Count De Gercourt, he hopes that he can combine the pleasure of the hunt for Madame De Tourvel's heart with the pleasure of helping the Marchioness a hand.  And who knows what else.

Les Liaisons Dangereuses is entirely told through 175 letters sent to and from everyone involved.  Letters that tell of the naieve innocence of the two young lovers, and the wickedness of the Viscount and the Marchioness.  Though there is no conversation in this novel -other than the one written in letters- and the action is to be made of the reports by the different letter-writers, the novel is more gripping than any of the movies made after it, despite it's age.  Valmont and De Merteuil come out of it as characters that call for both fascination and aversion, though Valmont gets a bit more sympathy as during his attempts to get Madame De Tourvel he seems to be, for the first time maybe, capable of love, where De Merteuil is someone who sees people purely as objects to be used and thrown away.

And it's when Valmont's love appears the real battle in this book becomes clear.  Not the scores De Merteuil and Valmont have to settle, but Valmont against De Merteuil, a battle Valmont cannot really win against this cold lady for whom love is a careful control over facial muscles and tears, and for whom even friends are just there to use.  After Valmont, his beloved Madame De Tourvel, and everyone else have been destroyed she remains as the victor, or at least, so it seems.

This must be one of the most cynical views on human relations ever written.  Surprisingly fresh and relevant despite it's age, this classic is one of the masterpieces of literature that seems to remain timeless.