On the run, Cora Sandoval must find the answers to why an ancient race of soul-stealers are determined to possess the pure energy of the Scintilla...or die trying.Learning the truth about herself was just the beginning.Tormented after a daring escape, and heartbroken from her good-bye with someone she loves and can never have, Cora must find a way to stop the Arrazi from murdering innocent humans and from violating, using, and killing the Scintilla for their powers.On the run with two others like her, they've relied on each other for survival. But their alliance of three means they're even more sought after by those who would do anything to capture them. They are determined to find out why.But it's not just the Arrazi who chase them. There's madness among races and deadly competition in the hunt for the trio. The Scintilla will soon be extinct if they don't solve the mystery of The Light Key. If they fail, the truth will stay buried forever and mankind will pay the ultimate price.