Widow's Bargain by Juliet Landon

When her ancestral home was beset by a dangerous band of reivers, Lady Ebony Moffat feared for her young son's safety. In a blind moment of frenzy, the widow struck a bargain with the men's leader - her body for her child's life.

Unbeknownst to Lady Ebony, Sir Alex Somers had raided Castle Kells seeking out traitors at the behest of the King of Scotland. And though he'd never harm her son, Alex couldn't help but be drawn to the raven-haired beauty's all-too-tempting offer. Still, Alex instinctively knew making love to Ebony would never be enough - unless she gave him both her body and her soul!