In a North African-inspired fantasy world, two sisters must fight to the death to win the crown. Sixteen-year-old Eva is a princess, born with the magick of marrow and blood--a dark and terrible magick that hasn't been seen for generations in the vibrant but fractured country of Myre. Its last known practitioner was Queen Raina, who toppled the native khimaer royalty and massacred thousands, including her own sister, eight generations ago, thus beginning the Rival Heir tradition. Living in Raina's long and dark shadow, Eva must now face her older sister, Isa, in a battle to the death if she hopes to ascend to the Ivory Throne--because in the Queendom of Myre only the strongest, most ruthless rulers survive. When Eva is attacked by an assassin just weeks before the battle with her sister, she discovers there is more to the attempt on her life than meets the eye--and it isn't just her sister who wants to see her dead. As tensions escalate, Eva is forced to turn to a fey instructor of mythic proportions and a mysterious and handsome khimaer prince for help in growing her magick into something to fear. Because despite the love she still has for her sister, Eva will have to choose: Isa's death or her own.