A hundred years from now, Kiera Lynn, the strongest spirit master alive, is betrayed and struck down by the four contract-bonded partners she trusted most, the people she thought would stand with her to the end. She opens her eyes again at fifteen, three hundred years in the past, her spirit core still dormant and her pockets empty, with nothing but the memory of exactly how and when each of them will turn on her. This time she means to strike first, hunting down her future enemies before they ever grow strong enough to betray her. But revenge doesn't stay simple for long. The knight she remembers as cold and rigid is, at this age, reckless, hot-blooded, and painfully sincere, practically a walking ray of sunshine. The Declan Cole she remembers as brutal is a starving, battered boy throwing himself between danger and the cub he's desperate to protect. The prophet she remembers as sharp-tongued and untouchable is instead chained half-starved at the top of a tower, forgotten by everyone. And the Wolfsbane Clan's young lord, who seems bright and easygoing on the surface, is quietly carrying a blood debt no one has ever avenged, bullied by the very people who should protect him. One by one, the enemies Kiera came back to kill turn out to be nothing like the monsters she remembers, and her carefully plotted path of vengeance starts pulling her somewhere she never expected to go.
