A pilgrim narrator, having lost his way, is guided by a revered classical poet through a terrifying, ordered realm of the damned. They descend through concentric regions where sinners receive symbolic punishments tailored to their transgressions, and the traveler meets a succession of historical and allegorical figures whose fates illustrate moral, political, and spiritual failings. The narrative alternates vivid, often grotesque imagery with reflective commentary on justice, sin, responsibility, and the possibility of redemption, presenting an ethical cosmology that prepares the narrator for a subsequent ascent toward purification and divine grace.