Her Heart’s Choice by Rose Pearson

One newly impoverished Marquess meets one relentlessly inquisitive Lady.

Lady Sarah has already lost one gentleman close to her and finding herself interested in a gentleman bearing an injury is not a wise choice – particularly when she discovers that he is heavily impoverished. Her heart refuses to be pulled away, however, and she begins seeking him out all the more.
Gideon, Marquess of Stoneleigh, has a problem to solve: someone injured him and stole a great deal of his wealth through less than scrupulous means. To regain his fortune, Gideon must put all of his efforts into solving the mystery – but finds himself distracted by the lovely and inquisitive Lady Sarah. Can he continue to pull himself away from her? And what will he do when he discovers that Lady Sarah and his loss of fortune are inextricably linked?