Riméane, Saïcha, and Myosotis Brimbelle, the millers’ children, are competing in the Adelphides for the first time. This annual tradition allows siblings to strengthen their bond and serve the community. But the noble contestants look down on these newcomers from the countryside. That is, until they are chosen for the Sacred Service, the most vital and perilous mission of all. And when a rebellious princess seeks to upend the Adelphides, the fate of the Brimbelle siblings is changed forever.