Dante and Virgil enter a forest that is not lively and green but rather dark and dismal. As they traverse the gloomy woods, they encounter a group of Harpies, which are creatures with the heads of women and the bodies of birds. 

The trees—dark, foreboding, and strangely sorrowful figures—contain the spirits of those who died by suicide. Dante listens sorrowfully to their tales of imprisonment within the trees; they feel pain when their branches are broken or their leaves are plucked. Although suicide was then considered murder and equated with the worst of all sins because it symbolized a rejection of God’s gift of life, the spirits, specifically an Italian named Pietro della Vigna, moralize on the nature of suicide and question whether it should be considered a sin.