Hex Allen can't do magic - a huge problem when everything from lights to locks is powered by simple spells that everyone can do. After years of feeling useless, Hex seizes the chance to change her future by journeying to the Wishing Wyrm, a legendary dragon that will grant a single wish once a century. Unfortunately, Hex isn't the only one after the wish, and every rival wish hunter has magic on their side. Every rival except the Clanksmiths, Cam and Fuse. Like Hex, they can't do magic, but they've learned to build clank, creations made using the mysterious, forgotten arts of science and engineering. After a fairy fiasco throws Hex and the Clanksmiths together, they agree to cooperate - for the time being. With the Clanksmiths' know-how and Hex's creativity, they outsmart monsters with everything from LEDs to electromagnets to water balloon launchers. But as they race to the Wishing Wyrm, Hex must decide between her friendship with the Clanksmiths and the wish that would give her a normal, magical life.