Married to a Rogue (Lords and Ladies #2)
Donna Simpson, Donna Lea Simpson

Baxter, the Marquess of Sedgely, was given to dark moods and an uncertain temper that doomed his marriage. Finding relief in travel, he spent five years gallivanting the Continent and has now returned to London with a comely young mistress—and a dangerous secret. Cavalier about his safety, he discovers a far greater concern—for just one look at Emily stirs a realization that while his life may be in danger, it is his heart that faces a more immediate peril.
When Emily’s young French suitor arouses suspicions that he may not be all that he appears and a unknown assailant makes several attempts on Baxter’s life, the two are driven to protect each other and surrender to a passionate reawakening—and neither will rest until they are safely in the arms of the only person they’ve ever loved.
* This books was originally published under the title Lady Delafont’s Dilemma.