The perfect stranger - Anne Gracie

With her signature spirit, Faith Merridew has left everything she's ever known for the man she thought was the love of her life. Instead he leaves her name-and dreams-in the dust. That is, until she crosses paths with Nicholas Blacklock, a Waterloo veteran, who offers to save her reputation with a marriage of convenience.

...and then get to know one other.

A hardened soldier, Nick hides a deadly secret-and tries to keep Faith at arm's length. But even though Nick can command legions of men with a word, his orders go sweetly ignored by his convenient bride. And as they come to know one another more deeply, she brings out in him things he thought dead: gentleness, laughterand love