Dukes Court for Keeps. A Gentleman's Guide to Courtship, #6

The duke must take a wife. But he'd rather kiss a Scottish matchmaker. The Duke of Clearford would like to marry for love, but his family's secret erotic lending library makes that impossible. If the library is discovered, his wife would be ruined. But if he marries a member of the library, someone already courting scandal, he won't have to risk an innocent's reputation. He's determined to do just that.
Until he meets Lady Emma Blackwood-beautiful, intelligent, and entirely off limits. Chased out of Edinburgh by her enraged father and a scandal she did not cause, Lady Emma is determined to restart her matchmaking practice in London with a prestigious client-the insufferable Duke of Clearford. He's handsome, attentive, a bit brooding, and thinks he knows everything about courtship. Her reputation can't survive it.His morals won't allow it.Yet attraction, unexpected and consuming, threatens to their loyalty to duty and obligation.
But disappearing sisters, a race to Scotland, and one room at an inn force them to question how much they're willing to sacrifice before giving in to the demands of their hearts.