The Blood Kingdom by Kate Cunningham (The Blood Folk, 1 of 3)

“A dark omen. An ominous gift. A chance encounter with a handsome stranger that no one else remembers. Aurelia’s life has always been dictated by court politics and the watchful eye of nobility. But the glamour of court life is an ever-tightening noose, one that will never allow her to marry the man she loves or question the decisions that are made for her future. A predictable, monotonous future. The only escape from the gilded cage surrounding her is in the books she pilfers from the library. Descriptions of places beyond the pristine palace walls. Stories of the monsters that prowled the Shades long ago. Tales of dark beings who possessed darker power and threatened to wipe out humanity. Creatures that have been dead for centuries, along with the magic that once ruled their world, if it ever existed at all. But when Aurelia’s father is murdered, the clues left behind will lead her into a world much older and much more dangerous than she ever could have imagined.” – back cover