Black Fire by Barbara Riefe

Black Fire - It will menace the lives of two frightened and desperate lovers. Lorna, a red-haired green-eyed beauty, and Paul, her handsome and roguish lover.

Black Fire - It will pursue the lovers across oceans and continents, from the shadowy evil of Constantinople to the wilds of Asia, from the storm-ravaged Black Sea to their only remaining hope of refuge - a horror house of carnal temptation.