The passage to the First Ring of the Seventh Circle of Hell takes Virgil and Dante through a ravine of broken rock. At the edge, the monstrous Minotaur threatens them, and they must slip past him while he rages to distraction. As they descend, Virgil notes that this rock had not yet fallen at the time of his previous journey into the depths of Hell. Coming into the ring, they see a river of blood: here boil the sinners who were violent against their neighbors. A group of Centaurs—creatures that are half man, half horse—stand on the bank of the river with bows and arrows. They shoot at any soul that tries to raise itself out of the river to a height too pleasant for the magnitude of his or her sin.
The head Centaur, Chiron, notices that Dante moves the rocks that he walks on as only a living soul would. He draws an arrow, but Virgil commands him to stand back, and he obeys. Because the broken rocks make the ring treacherous to navigate, Virgil also asks that a Centaur be provided to guide them through the ring around the boiling blood. Chiron provides one named Nessus, on whose back Dante climbs.
Leading Virgil and Dante through the ring, Nessus names some of the more notable souls punished here, including one called Alexander (probably Alexander the Great), Dionysius, and Atilla the Hun. Those who lived as tyrants, and thus perpetrated violence on whole populations, lie in the deepest parts of the river. After fording the river at a shallow stretch, Nessus leaves the travelers, who continue on into the Second Ring.
In the Second Ring of the Seventh Circle of Hell, Virgil and Dante enter a strange wood filled with black and gnarled trees. Dante hears many cries of suffering but cannot see the souls that utter them. Virgil cryptically advises him to snap a twig off of one of the trees. He does so, and the tree cries out in pain, to Dante’s amazement. Blood begins to trickle down its bark. The souls in this ring—those who were violent against themselves or their possessions (Suicides and Squanderers, respectively)—have been transformed into trees.
Virgil tells the damaged tree-soul to tell his story to Dante so that Dante may spread the story on Earth. The tree-soul informs them that in life he was Pier della Vigna, an advisor to Emperor Frederick, and that he was a moral and admirable man. But when an envious group of scheming courtiers blackened his name with lies, he felt such shame that he took his own life.
Dante then asks how the souls here came to be in their current state. The tree-soul explains that when Minos first casts souls here, they take root and grow as saplings. They then are wounded and pecked by Harpies—foul creatures that are half woman, half bird. When a tree-soul’s branch is broken, it causes the soul the same pain as dismemberment. When the time comes for all souls to retrieve their bodies, these souls will not reunite fully with theirs, because they discarded them willingly. Instead, the returned bodies will be hung on the soul-trees’ branches, forcing each soul to see and feel constantly the human form that it rejected in life.