Dante and Virgil stop to look in awe at the Hellgate, on which encouraging words like "ABANDON EVERY HOPE, [YOU] WHO ENTER HERE" appear.
There is more to the inscription, which describes the origins of Hell—how it was made by "Justice," "the Highest Wisdom," and "Primal Love."
Dante tells Virgil he doesn’t understand the inscription.
Virgil, in his sage way, doesn’t really answer Dante’s question, but tells him to be brave. He also describes Hell’s sinners as people who have "lost the good of the intellect." (This is a good place to stick a big bright sticky note because this is an Important Concept.)
Dante’s first impression of Hell: it’s noisy. It’s full of "strange utterances, horrible pronouncements, / accents of anger, words of suffering, / and voices shrill and faint, and beating hands…"
Horrified, Dante asks Virgil who these people are that scream so loudly.
Virgil explains that they’re neutrals, people who failed to choose either good or evil in their lifetimes and so are condemned to exist in a kind of ante-Inferno...pre-Hell, if you will. The "coward angels" are here too—those that sided with neither God nor Lucifer in the great battle that created the Devil.
When Dante repeats his question, Virgil (slightly peeved) answers shortly:
These sinners have "no hope in death" and their entire existence is driven by envy for any other kind of existence… even one in the true circles of Hell. Virgil says this so quickly and tersely that he implies that these sinners aren’t even worth wasting many words over.
While sightseeing, Dante notices the neutrals’ punishment: various insects sting their naked bodies, irritating them and making them run around in big circles under a long banner. Dante is blown away by the sheer number of them; in other words, there are a lot of neutrals.
Among the horde, Dante recognizes the one "who made […] the great refusal." Scholars have interpreted this sinner as Pope Celestine V, who abdicated his papal seat just five months after taking office. This paved the way for the election of Pope Boniface VIII, whom Dante hates with a passion.
Dante observes a big crowd of people gathering on the banks of a big river and asks Virgil why they seem so eager to cross the river.
Our wise man tells Dante to quiet down; he’ll find out why when they actually get there. "There" being the banks of the river Acheron, one of the five rivers of the Greek Underworld.
When they do get there, Virgil doesn’t even get the chance to explain before an old man with a long white beard comes up to them and basically says, "No chance the two of you are getting on my boat. Only dead people allowed." This guy is Charon, the ferryman that takes people across the river.
Then Virgil gets all up in Charon’s face and one-ups him with "God sent us, so let us through." Or something like that.
So Charon is forced to ferry them across, but he’s pouty and sullen about it.
Dante, in poet mode, compares all the dead souls gathering on the riverbanks to falling leaves in autumn and later to hunting falcons returning to their masters when called. Dante is big on metaphors.
Virgil explains that only sinners ever have to undertake this crossing.
All of a sudden, an earthquake hits, complete with a tornado and a "blood-red light."