The Wolf Duke (Valor of Vinehill #2) by K.J. Jackson

This is a really deep and emotional story. An accident makes a woman seeking vengeance lose her memory of the past six months. She learns exactly the man that the Duke is. Set against northern England and the Scotland border, Reiner will follow Lady Sloane anywhere, because she has stolen his heart. Betrayals and lies will be the means to uncovering the treachery, but it will mean an unbreakable trust must be formed. I love Reiner and Sloane together. Theirs is a love that will stand the test of time.