Don’t Judge a Duke by His Cover by Emily E K Murdoch

Lawrence, Duke of Penshaw, is undercover and getting punched on a daily basis.

Devastated by the murder of his brother by a traitor to the Crown, Lawrence agrees to leave his identity as Duke behind to go undercover at an illegal boxing ring in London. He’s waiting for the killer to return from France, and absolutely must not get distracted. Especially by a beauty from Society who absolutely should not be here.
Julia Dryden knows her mother would be scandalized by her presence at the boxing matches—it flies in the face of their agreement for her to choose a husband by Easter. After all, she isn’t getting any younger.
But her eye is caught by a tall, handsome man who gives everything in the ring and seems to have no fear of danger.
From two different worlds—but not the ones she thinks—Julia has no idea the man she’s falling in love with is not a common rogue.
And Lawrence has to keep it that way for if he loses focus, just for a moment, he may lose everything.

The chance to catch a killer, put a traitor behind bars, revenge his brother…and Julia’s heart.