Lord Perfect - Number 3 in series

Tall, dark, and handsome, the heir to the Earl of Hargate, Benedict Carsington, is known for his impeccable manners and good breeding. Benedict knows all the rules and has no trouble following them - until Bathsheba Wingate enters his life. Bathsheba Wingate belongs to the rotten branch of the DeLucey family: a notorious bunch of liars, frauds and swindlers. Small wonder her husband's high-born family disowned him.
Now widowed, Bathsheba is determined to give her young daughter a proper upbringing. Nothing and no one will disrupt her plans. Then Bathseba's hoyden daughter lures Benedict's precocious nephew into a quest for a legendary treasure. To recover the would-be knights errant, Benedict and Bathsheba must embark on a rescue mission that puts them in dangerous, intimate proximity. Fortunately, Benedict is in perfect control - despite his mad desire to break all the rules.
Perfect control. Really.