Broden by Hazel Hunter

A Frenchwoman lands among the clan during a battle, a grim harbinger of things to come.
For Mariena Douet, actions speak louder than words. At her first opportunity, she puts the clan on notice: no one is to touch her. To make certain they understand, she deftly steals a blade and draws Mag Raith blood.
Broden Mag Raith, who has patiently waited for his lover for months, now can’t wait to get away from her. The gentle woman of his dreams turns out to be a killer as lethal as any of his brothers.
But the clan may come to appreciate her skills when the unthinkable happens: their enemy breaches the walls of the castle.