Since their little tiff over the Présidente de Tourvel, the Vicomte de Valmont and the Marquise de Merteuil have not been writing to each other. In Letter Ten, Merteuil relents and writes to Valmont to scold him for not sending her a letter first. She continues to be annoyed by his affection for Tourvel and challenges his courage, since he is not rushing to seduce the Présidente. She also informs Valmont that the Chevalier Danceny has begun to occupy a special place in her heart and her bedroom. She recently engaged him in a wild goose chase all over town, which culminated at the end of the day in her romantic cottage, where a night of passion ensued.
Tourvel replies to Madame Volanges to tell her, in Letter Eleven, that Valmont has "laid down his arms" ("déposé ses armes"). She thinks that since she has higher morals than other women, Valmont does not dare treat her as he treats all other women. Her interest in him now, she claims, is just to report on his conduct to Volanges.
Letter Twelve is a short note from Cécile to inform the Marquise de Merteuil that she and her mother will be unable to come to the opera, since her mother is sick.
The Marquise replies to Cécile (Letter Thirteen), to invite her to sing with Danceny.
In turn, Cécile sends a gossipy Letter Fourteen to Sophie, in which she details her recent interactions with the glamorous Marquise and the dreamy Chevalier.
Valmont also has news for his gossip-partner. He writes to Merteuil (Letter Fifteen) to tell her about his newest exploits with Tourvel. But before getting down to business, he pretends to be jealous of Danceny and hopes that the Marquise will not leave him forever. As for the Tourvel report, the Présidente is having one of her servants follow him so that she will know the details of all of his activities. This provides Valmont with endless amusement.