Dark Passion (The Brethren Series, Book Three‪)‬

Augustus Noble is a man with secrets. His entire life has been built on half-truths, betrayals, and lies--desperate measures ot keep the woman he loves, Eleanor Trevilian-Noble, as his own. The patriarch of the Brethren, he has struggled for centuries to create an empire of wealth and prestige for her. Now all that he has fought for is in jeopardy--his grandson Brandon has risked it all in a desperate bid for independence and freedom. And just as Augustus can't allow Brandon to escape the ages-old traditions of the Brethren race, he also can't let the Brethren--and especially his longtime nemesis--discover a truth that, if revealed, would see them all killed.