Luna's home city of Cresfield has been overrun by Eternal, an armed cult that spreads through deception—promising "Eternal happiness to All" and using that promise to conquer town after town. Luna finds unlikely allies in the people she meets: Dithen the wandering traveler, Nack the priest, Xavier the scholar, and Layzel the comedian. Together they push back against a cult that is harder to fight than it first appears, because it does not fight with weapons alone.