Adele, queen of the fairies, longs for the past when fairies ruled the skies and humans trembled on the ground below. She's enthralled a human tinker to finish her grand machine and restart the human-fairy war. Only the tinker's twin sister can break the spell.

Five years have passed. The worlds above and below have recovered and changed. The fairies from the Clockwork Kingdom return every year, asking for Dale’s help in vain. This year, Cornelius, the head of the fairies, brings dread news: Kostya has returned. The Maker has taught herself what she could about magic, but no teacher has ever arrived. Finally, a herald manages to break through the spells surrounding the town to warn Nora that something, perhaps a monster, has been keeping them at bay. And it is stalking her for her power, and her life. Can Nora get away before the monster enthralls her? What price will Dale pay to keep his sister free? And who is the monster?