The Scot's Oath (Sons of Scotland #3)
Heather Grothaus

When Padraig Boyd learns he is the sole legitimate heir to a Northumberland manor, he flees the impoverished fishing isle of Caedmaray to claim the estate and clear his missing father of criminal accusations. Arriving at imposing, mysterious Darlyrede House, he faces a formidable enemy in the castle's occupying lord, a challenging battle--and an unexpected helper . . .
With deadly traps awaiting him at every turn, Padraig finds an ally in Beryl, a beautiful maidservant who schools the rugged Scotsman in the rules of nobility. But as a tempting passion draws them in, so do the secrets that brought the cunning lass to this house of scandal and deceit. Unmasking her intentions is a high-stakes
game--one that may arm Padraig with the most dangerous of weapons: the truth.