Weary of her very public life in Paris, an aging courtesan takes her orphaned niece from her convent home and relocates to Monte Carlo to begin a new life. Determined to bury the past, the courtesan Madame Bluet becomes the respectable Countess de Secret, and her niece Mistral, Mademoiselle Phantome. Soon, the secretive Countess and the beautiful Mlle. Phantome are the talk of Monte Carlo. Mistral finds herself surrounded by admirers - some with less than honorable intentions, while her aunt plots a long-awaited revenge. Will Mistral's chance for happiness be destroyed when her aunt's plot and past are revealed?
