Dante continues to look at the sowers of discord in amazement, and Virgil tells him that they must hurry and continue with their journey. There are far too many souls here for Dante to speak with all of them. Dante says that he thinks a family member of his might be here, but Virgil tells him that this person, Geri del Bello, already passed by and Dante didn't notice him.
Even among such wonders and famous souls, Dante's main concern is to find his family member. Local, personal, earthly concerns again take precedence for Dante over seemingly loftier issues—like continuing on his holy journey.
Virgil says that Geri looked angrily at Dante, and Dante says that this must be because no one has avenged Geri's violent death yet. Dante pities Geri. Dante and Virgil walk along until they can see the next trench—except that, as Dante remarks, there is no light for it to be seen by. Dante has to cover his ears because the shrieks of pain coming from this tenth and final trench are so loud.
Virgil's description of Geri shows that hell and earth are significantly interrelated. Geri is angry in hell because his death goes unavenged on earth. And if someone were to avenge him on earth, his behavior in hell would change. As they get deeper into hell, the light disappears.
The souls here suffer from horrible diseases and sicknesses, worse than any on earth. Dante and Virgil walk down into the trench and Dante sees that here falsifiers are punished. The souls are heaped on the ground or crawling around, suffering from horrible illnesses. Dante sees two souls sitting, covered in scabs, scratching themselves violently because they suffer from a terrible, unending itch. Dante compares their scratching to someone scraping the scales off a fish with a knife.
Dante's simile about scratching creates a strange likeness between something on earth and something on hell. However, the grotesque correspondence (between a fish being scaled and a human body being scratched) emphasizes the horrible strangeness of hell.
Virgil asks these two if anyone nearby is Italian and tells them that he is leading a living man through hell. The two souls (and others who heard Virgil) draw near in amazement. Virgil encourages Dante to ask them whatever he wants. Dante tells the spirits to identify themselves, so that their names can live on in fame on earth.
Dante's status as an earthly living soul in hell is again a source of marvel. Virgil and Dante are again mostly interested in speaking with sinners from Italy.
One spirit introduces himself as Griffolino d'Arezzo, a scientist who tricked a nobleman of Siena by promising impossible miracles. He is punished here, though, for his pursuit of alchemy (falsifying precious metals). Dante criticizes the people of Siena loudly and another spirit agrees with him. This spirit identifies himself as Capocchio, also guilty of alchemy.
After hearing Griffolino, Dante does not criticize him, or the pursuit of alchemy, or sin. Rather, he uses Griffolino as a chance to insult Griffolino's home city of Siena. Dante's fantastical journey is often used like this as a way of criticizing the cities and people of his own time.