Fighting evil is a hobby, fending off marriage-minded women's chore. When Lord Charles Percy seizes a highwayman robbing a carriage in broad daylight, he conceals his identity to the debutante he rescues. It wouldn't do for her to know a member of the peerage is secretly in pursuit of the infamous Black Diamond. Instead, he claims to be a mere mister who happened along perchance at an opportune moment. Despite the fact she's a woman, the Honorable Henrietta Allendale doesn't need a man to fight her battles, especially one whom she suspects is hiding things of import. So why can she not stop thinking about the gallant Mister Percy and his selfless act of heroism on her behalf? Meeting again in London, Charles begins to enjoy verbally sparring with the intrepid young woman, and his heart is soon captivated as well. But he's playing a deep game, and Henrietta's presence in his life puts hers at risk. When a successful rescue results in possible scandal, the baron's biggest challenge will be to convince the marriage-adverse young woman that his love is true.