Arwen Valondale, who never imagined herself the brave type, offers her life to save her brother and wakes to find herself a captive in the ruthless Onyx Kingdom—forced to wield her rare healing magic for its soldiers. Surrounded by ancient, sinister forests and dark enchantments, she must rely on an infuriatingly cunning fellow prisoner to survive—and maybe discover a spark of power—and feelings—she never expected.