The Soul Hunter — Merabeth James

Most would say that the Ravynne sisters have led a charmed life always managing to escape intact from one horrific adventure after another…one evil entity after another. Fiercely loyal to each other, they have battled back the darkness no matter what form it took, but what would happen if they discovered that the darkness was a seed each carried?
A suspicious letter from their brother, Allyn, has them traveling to haunted Muirwind Manor on the bleak moors not far from Cape Wrath, Scotland. There they discover secrets long buried that threaten both their lives and their souls.