At the entrance to the Third Circle, Dante is greeted by a freezing flurry of non-stop rain, sleet, snow, and hail. There, Dante and Virgil encounter Cerberus, a three-headed canine responsible for guarding the gates of the Third Circle. He is a fearsome beast, but Virgil successfully pacifies the dog's aggression by hurling dirt from the ground into its three mouths. As Cerberus struggles, they pass into the Third Circle, a muddy plain filled with gluttons lying waist-deep in the swamp. 

While traversing the mud, Dante and Virgil encounter a glutton named Ciacco, who hails from Florence. He hails the visitors and engages them in conversation, predicting that the ongoing political conflict in Florence between the Black—pro-papal—and White—pro-imperial—factions will persist and eventually escalate into violent confrontation. According to Ciacco, the White party will eventually triumph over their adversaries, but their power will decline within three days. After this period, the other faction will regain power.

Dante inquires about the whereabouts of Tegghiaio and Farinata, Rusticucci, Mosca, Arrigo, and other less-than-virtuous Florentines; Ciacco reveals that they can be found further down in the depths of Hell. Ciacco, as his final wish, requests Dante to remember his name when he returns to the world.

After speaking with Francesca and Ciacco, Dante struggles with his pity for the suffering of these souls, so Virgil warns Dante that they will encounter more misery in the future. They proceed and encounter Plutus, a formidable adversary and Cerberus's counterpart.