It's a world where order is maintained by three great factions, the Church which holds the greatest authority, the Order of Clausius which possesses influence on par with the Church, vast assets and military might, and lastly the Guild of Commerce, an association of merchants and artisans alike.
The alchemist Kusler who was captured and imprisoned because he committed the offence of trying to burn a saint's bones, sold his skills and talents to the Order of Clausius. Together with an old friend, Welland, they were then dispatched towards the town of Grubetti which was close to the front lines.
And then at a workshop in Grubetti which boasted advanced equipment due to being near the front lines, Kusler met the devout nun Urle Fenesis who had introduced herself as a "watchdog".