The sodomites are forced to run endlessly through flames that rain down on them from the sky. Dante is horrified by the scene and asks Virgil why these souls are being punished in this manner. Virgil explains that these sinners have violated the natural order and engaged in unnatural acts, and as such, they are subjected to unnatural and everlasting torment.
Among the sodomites, Dante encounters Brunetto Latini, his former teacher and mentor from Florence. Brunetto expresses his gratitude to Dante for being remembered and asks for his help in carrying his burden of sin. Dante is deeply moved and promises to fulfill his request.
As they continue their journey, Dante asks Virgil about the nature of sodomy and the reasons why it is considered such a grave sin. Virgil provides a theological and philosophical explanation, drawing upon both religious teachings and ancient Greek philosophies, to illustrate the gravity of this particular sin.
Canto 15 concludes with Dante and Virgil departing from the realm of the sodomites and proceeding further into Hell.