His Dark and Dangerous Ways by Edith Layton

Simon Atwood, Lord Granger, once gave all for his country—and paid the price. Now, his handsome face haunted by a secret sorrow, Simon has undertaken a mission far closer to home, but no less dangerous. And though he hesitates to risk her safety, he must seek the help of Jane Chatham, an enchanting dance teacher who could prove a worthy partner—in espionage and in love.

Forced to live by her wiles far from her well-bred country upbringing, Jane Chatham is suspicious of every man's intentions, even those of a gentleman like Simon Atwood. After all, she knows nothing of this enigmatic nobleman, and has no reason to believe his promises. Keeping him at a distance should prove simple for the resourceful, quick-witted beauty . . . until she finds herself mesmerized by Simon's dark and dangerous ways, consumed by a passion that puts her very life at stake.