Leaving the forest behind, Dante and Virgil walk along the narrow path made by the banks of the Phlegethon. A large group of souls sees the two poets, and one of them comes forward and accosts Dante. Dante looks at the spirit's face and recognizes him as Brunetto Latini, his old teacher. Dante asks to sit with Brunetto to talk, but Brunetto says that if he rests for even a second, he would have to lie in the sands for a hundred years. He tells Dante to keep walking, so he can walk alongside him.
Latini is eager to speak with someone he knew on earth. Dante's inclusion of his friend and fellow Guelph in The Inferno is ambiguously both complimentary and critical. Dante immortalizes Latini in his famous poem, but by including him in hell also accuses him of being an impious sinner, in this case someone who practiced sodomy. At the same time, one could argue that by including a friend in hell Dante is rightly insisting that following the right path is the only way to avoid hell and get to heaven. Had Dante only put his political rivals—such as Ghibellines or Black Guelphs—in hell, it would have implied that he was being unfair in who he assigned to hell, prioritizing politics over conscience.
Dante explains to Brunetto how he found himself in the dark wood and is now being guided by Virgil through hell. Brunetto encourages him to keep on his journey so that he will reach heaven. He says that he regrets he died early, or else he would have given Dante advice and counsel in life. He predicts that "Fortune has honours for [Dante]," (15.70) and Dante laments Brunetto's death, calling him a father figure. Dante is thankful for Brunetto's prediction of good fortune, but does not put too much stock in it, saying he is ready for whatever capricious Fortune may bring him.
Latini predicts great fortune and fame for Dante (which, in the context of Dante's poem is a kind of self-fulfilling prophecy). Like a good, pious soul who has learned well from his master Virgil, Dante avoids arrogance and says that he will be ready for whatever God sends his way through Fortune.
Dante asks Brunetto to name some of the more famous sinners who are in his group, wandering about the desert sands. Brunetto says that the group is full of learned men and scholars, who sinned against nature and their own bodies. (These are all categorized under the general term of Sodomites.) He names Priscian and Francis of Accorso and, before running off, asks Dante to remember his work, the Thesaurus, in which he lives on. As Brunetto leaves, Dante thinks that his friend looks like the winning runner in a race.
Latini's request for Dante to mention his great work shows how important some kind of fame (whether achieved through great deeds or through literary achievement) is for souls like him. Dante's odd comparison of him to a runner winning a race is perhaps a kind gesture toward his friend, an attempt to describe him in some good way, even as he is doomed to hell.