Greydon, the Viscount Rushcliffe, is content with his life as a Bow Street Runner, but it all comes to a jarring end when his older brother is murdered. He is now an heir to an earldom—a position he never wanted. As he is trying to come to grips with the newfound shackle on his life, Lady Enid—the only woman that he is inexplicably drawn to—comes to him for help to let his brother's murderer go free.

In the eyes of London society, Lady Enid Longbourn is ruined. Though the ton whispers about how she returned home after the death of her husband, any speculation remains just that: gossip. Her own father doesn't even want her home, but she is determined to give her daughter the future she deserves. However, when her friend is arrested for murder, she knows it must be a terrible mistake and is determined to do whatever it takes to ensure she is set free.

After Enid proves herself to be reckless, Greydon agrees to take the case, but only to keep this vexing woman safe. It should be a straightforward investigation, but it becomes increasingly tangled and confusing. The greatest complication is the one that he didn't see coming: he never thought they would fall in love.