The Heart of a Scoundrel by Christi Caldwell

Ruthless, wicked, and dark, the Marquess of Rutland rouses terror in the breast of ladies and nobleman alike. All Edmund wants in life is power. After he was publically humiliated by his one love Lady Margaret, he vowed vengeance, using Margaret’s niece, as his pawn. Except, he’s thwarted by another, more enticing target—Miss Phoebe Barrett.
Miss Phoebe Barrett knows precisely the shame she’s been born to. Because her father is a shocking letch she’s learned to form her own opinions on a person’s worth. After a chance meeting with the Marquess of Rutland, she is captivated by the mysterious man. He, too, is a victim of society’s scorn, but the more encounters she has with Edmund, the more she knows there is powerful depth and emotion to the jaded marquess.
The lady wreaks havoc on Edmund’s plans for revenge and he finds he wants Phoebe, at all costs. As she’s drawn into the darkness of his world, Phoebe risks being destroyed by Edmund’s ruthlessness. And Phoebe who desires love at all costs, has to determine if she can ever truly trust the heart of a scoundrel.