For Ash Woods, practicing alchemy is a crime. Only an elite few are legally permitted to study the science of magi - so when Ash is rejected by Lancaster College of Alchemic Science, he takes a job as the school's groundskeeper instead, forced to learn alchemy in secret. When he's discovered by the condescending and brilliant apprentice Ramsay Thorne, Ash is sure he's about to be arrested - but instead of calling the reds, Ramsay surprises Ash by making him an offer: Ramsay will keep Ash's secret if he helps her find the legendary Book of Source, a sacred text that gives its reader extraordinary power. As Ash and Ramsay work together and their feelings for each other grow, Ash discovers their mission is more dangerous than he imagined, pitting them against influential and powerful alchemists - Ash's estranged father included. Ash's journey takes him through the cities and wilds across New Anglia, forcing him to discover his own definition of true power and how far he and other alchemists will go to seize it.