Relieved that Virgil is not seriously upset with him, Dante follows him forward. Dante can hardly see anything in the darkness, but hears a loud horn that makes thunder seem quiet by comparison. Dante thinks that he sees a group of towers ahead and asks Virgil what it is. Virgil tells him that he is seeing falsely in the darkness and that he will see more clearly when they get there.
Virgil tells Dante that what he sees are not towers, but actually giants stuck from their navels down into the ground. As they approach the giants, Dante indeed sees their shapes more clearly. The giants are arranged in a circle surrounding a well. Dante looks in wonder at their enormous size.
Dante is astounded at the otherworldly sight of these giants, whom he mistook for huge towers.
One of the giants tries to speak, but no intelligible words come. Virgil tells the giant not to try to speak, but to stick to its horn, which hangs around its neck (and which Dante heard just earlier). Virgil identifies this giant as Nimrod, who was responsible for the construction of the failed tower of Babel. (In a biblical story, the tower of Babel was supposed to reach to heaven. When the overreaching tower crumbled and was destroyed by God, the one language that all humans spoke fractured into all the different languages we now have.)
Dante then sees an even taller giant, with its hands bound by a huge iron chain. Virgil names him as Ephialtes, who in classical mythology tried to climb to the top of Olympus to overthrow Jupiter. Ephialtes shakes in his chains, causing the ground to tremble. Virgil tells Dante that they will find Antaeus, a giant who is unchained and can carry them down the well surrounded by these giants.
Dante mixes the Biblical character Nimrod with the giants of Greek mythology, making them into the same kind of creature. Ephialtes' affront to Jupiter becomes, for Dante, an offense against God.
Virgil addresses the fearful giant Antaeus and tells him to carry Dante and him safely down the well, since Dante, who is alive, can report his name back on earth, guaranteeing him fame. Antaeus outstretches a hand, and Dante and Virgil climb onto it. Dante is scared to travel this way, but Antaeus reaches down and safely deposits the two poets in the ninth circle of hell, where Judas and Lucifer are held.
Virgil's powerful words turn this terrifying giant into a helpful aid for Dante's journey to the center of hell, where the worst of the sinners are held: the betrayers, including the two most awful betrayers, the betrayers of Jesus and God.