Blackmail
His only desire was to use her

That horrible damning letter! If Lee didn't become Gilles de Chauvigny's temporary wife he'd show it to her real fiancé.

That Gilles could disrupt her life so carelessly, so callously just to be rid of a too possessive mistress--outraged Lee, but she was powerless to stop him.

Then, later, she didn't want to, for she had fallen hopelessly in love with him. Hopelessly because his spurned lover vowed to have him back. Hopelessly because Gilles felt nothing for her.

Hero: Gilles de Chauvigny
Heroine: Lee Raven