In the small town of Rannai, a badger doctor named Egoan is tasked by Duke Leopoldino with curing a young wolf—Cadgan—of a mysterious and unknown illness. The doctor's son and assistant, Hector, begins to form a close bond with the wolf.
Nine years later, Hector returns to Rannai as a doctor at the behest of Leopoldino's son, the mercurial Duke Manoel, whose demands of expeditions into the reportedly demon-infested forest have left the town's adventurers in need of medical assistance. Upon reuniting with Cadgan, however, Hector discovers a completely different wolf than the one he once knew—one who is unable to rekindle the connection between them. In a moment of despair and vulnerability, Hector is faced with a decision that will impact the course of his life in Rannai.