The Shades of Winter — Morgan Smith

An aging band of sea raiders set out on one last voyage of revenge, and get a whole lot more than they bargained for.
Tam Isliefsdottir wasn't planning to end her life in a futile attempt for vengeance, but when your brothers- and sisters-in-arms need you, what can you do? Leaving her son and her granddaughter behind and sailing to the shadowy island of Alvandir, she expected to die gloriously for the sake of her country, her king, and her own reputation.
Nothing is as it is supposed to be, however, and it hasn't been for the last twenty years. Tam and her Kyndred are in for the surprise of their lives.