A young woman in Paris discovers the dangers of passion when she pursues an anonymous affair with a married man.

Elle has always had a taste for older, married men, even when she was a teenager. Now, at twenty and living in Paris, she leads a lighthearted and carefree life until she meets a man she calls "Mister." Elle knows all she needs to know about him—that he's married, a devoted father of five, and a devotee of classic erotic literature.

Beginning with their first frenzied hook-up in a hotel room in the fifteenth arrondissement, Monsieur details the clandestine Tuesday morning hotel meetings and fleeting phone calls that span several months of sexual adventure. Generous with her body and never lacking imagination—or partners, both men and women—Elle illuminates her deviations in a fearless and ferocious confessional. From her seduction of Monsieur to its devastating aftermath, from the height of desire to a descent into cruel fantasy, Elle reveals the uninhibited fulfillment and stunning disenchantment of a twenty-first-century Lolita.