War has torn the world in two, and the magic that was meant to save Rabid's people has become their greatest threat. When ancient enemies draw her people deep into the frozen north, Rabid and Stone discover that some battles can't be won with swords—and that the darkness they're fighting may be closer than they ever imagined. Pulled apart by impossible choices and hunted by creatures born of shadow, they must decide: cling to the slowly dying light, or embrace the very powers they've sworn to destroy.