A Shade of Blood (A Shade of Vampire, #2) by Bella Forrest
Synopsis: When Sofia Claremont was kidnapped to a sunless island, uncharted by any map and ruled by the most powerful vampire coven on the planet, she believed she’d forever be a captive of its dark ruler, Derek Novak. Now, after months of surviving an endless night, the morning sun may soon rise again for Sofia. Something has possessed Derek’s heart and he offers her a gift no human slave has ever been…