Henri Husson is older and wiser, but still every bit the sadist libertine who lusted after and callously taunted Séverine, a frigid bourgeois wife of a Parisian surgeon who lived out her sexual fantasies through a day job at an exclusive brothel under the moniker "Belle de jour." Severine was found out by family "friend" Henri Husson, but when she refused to have sex with him during his unexpected visit to the brothel, he acrimoniously threatened to reveal Séverine's secret to her husband, Pierre. Tragedy struck when Pierre was shot by one of Séverine's jealous clients. Left mute and paralytic, Pierre took a visit from Husson, but what Husson told Pierre in their moment together is a secret through which Séverine was left to suffer. Thirty-eight years later, Husson spots Severine sitting a few rows away from him at a concert in Paris. Anxious to engage her, Husson rushes after Séverine at the concert's end, but she has no interest in revisiting her past and manages to elude her former adversary. Yet Husson is persistent and with a little investigative toil, he traces Séverine back to her hotel. They come close to meeting again, but she avoids him by all means. That is, until Husson's stalking begins to wear on her. Eventually, he manages to gain her attention with the intention of revealing the secret that he alone can unfold. After years of lingering torment, Séverine is finally offered an opportunity to uncover the truth about what her husband learned--or didn't learn--about her during that fateful visit with Husson so many years earlier. Now a widow, she agrees to meet with Husson over dinner, where she expects that all will be revealed. What she doesn't know is that Husson has his own agenda and that their dinner together will be much more than she bargained for.