Aeneas and the Trojans arrive at Cumae. While his men go hunting and exploring, Aeneas climbs to Apollo's temple and the Sibyl's cave. Long ago, Daedalus flew here (using the wings he constructed) and built this temple for Apollo. The doors to the temple depict the story of the Minotaur, who Daedalus helped to outwit. But Daedalus was too sad to depict the story of Icarus, his fallen son, on the doors.
The doors of the temple allow Virgil to use ecphrasis, which is a poetic technique when a description of a work of art allows the author to tell a story-within-a-story—in this case, exploring the myths of Daedalus. Ecphrasis also occurred back in Book 1 with the Trojan War stories on Dido's temple.
The Sybil urges Aeneas and Achates to sacrifice animals to Apollo. They do, and she calls out, her voice echoing through a hundred doors. She sees Apollo and enters a trance, possessed by the god. Aeneas asks to hear his fate, promising to build Apollo a temple and honor him as guardian of his future kingdom. As Helenus had counseled, Aeneas asks the Sibyl not to write the prophecy on easily-scattered leaves, but to say it aloud. The violently possessed Sibyl answers as the hundred doors fly open. The Trojans will reach and rule in Italy, but must first fight a terrible war.
This spooky, dramatic scene gives us the clearest articulation yet of Aeneas's fate. The Sibyl's violent possession intensely demonstrates the power of fate and the gods, and hints at the danger of defying them. Apparently, Dido's deathbed wishes will come true, and Aeneas will have to watch his companions die before fulfilling his fate.
Aeneas asks how he can descend to the Underworld to see Anchises again. The Sibyl answers that it's easy to go down to hell, but difficult to come back up. To visit the ghosts, he must find a nearby tree with a golden bough, which he must present as a gift to Proserpina, queen of the Underworld. Only those fated to go to the Underworld can remove the bough. But before all that, he should bury the body of his friend that has washed up on the shore.
The golden bough will be the first physical manifestation of Aeneas's fate, and it will give him a decisive yes or no answer about his suitability for this rare mission to the Underworld. It's fitting that this symbol comes from the natural world—this is beyond the realm of human creation.
Having located the body of their countryman Misenus on the shore, the Trojans build a tomb for him. Aeneas prays to find the tree with the golden bough, and Venus sends two doves to help him. He finds the tree near the entrance to the Underworld, and successfully removes the bough.
Unsurprisingly, Aeneas succeeds in taking the bough. But again, his success has depended in part on outside help. Fulfilling his destiny is a team effort. Though it's also worth noting that he piously followed the advice of the Sibyl to prepare the tomb for Misenus before searching out the golden bough.
The Trojans bury Misenus, then Aeneas performs sacrifices for good luck in the Underworld. The Sibyl leads Aeneas to the Underworld's entrance. Monsters and embodiments of Hunger, War, and Discord (among many others) stand before the entrance. Aeneas wants to fight them with his sword, but the Sibyl tells him that the sword will have no effect on their ghostly forms. Heading deeper into the Underworld, they reach Charon, who will ferry them across the river Styx.
In this passage Virgil transforms ideas like War and Hunger into godlike bodies—adding weight to the argument that the other gods in the Aeneid's might also be more like embodied human wishes than full, accountable characters.
The shores of the river are crowded with the ghosts of those who were not properly buried and therefore must wait a hundred years before crossing the river. Aeneas sees the ghost of Palinurus among those who are waiting. Aeneas says that Palinurus shouldn't have died, since a prophecy predicted that he'd reach Italy. In fact, Palinurus explains that after falling from the ship he did float to Italy, only to be killed by locals. He asks for a proper burial, or for Aeneas to help him cross the river. The Sibyl tells him not to cheat his fate by trying to get across the river before he is destined to, but comforts him by saying that he will be long remembered on Earth.
As we saw with the bleeding plants in Book 3, proper burials are key to a good death. Palinurus still hasn't accepted his fate.
Charon tells Aeneas he cannot take a living person across the river, but the Sibyl displays the golden bough, and Charon ceases his objections. After crossing, the Sibyl subdues the three-headed guard dog Cerberus with drugged cake. After passing Cerberus, Aeneas and Sibyl encounter a variety of dead people, who are being categorized (babies, suicides, those who died for love, etc) or, for particularly bad people, judged for punishment. Among the dead-for-love group wanders Dido. Aeneas tells her he left her unwillingly, begging her to stay, but she angrily ignores him, and runs to Sychaeus, who "meets her love with love."
Dido's reappearance allows her to display some of the dignity she lost during her time with Aeneas. Now, he's the beggar and she's the one with the power to ignore him. She's reunited with her true love, Sychaeus, showing that death and the Underworld need not be tragic.
The fascinated ghosts crowd around Aeneas—except for the fallen Greeks, who are frightened of him and avoid him. Aeneas speaks with the disfigured Deiphobus, son of Priam, who describes how his wife betrayed him to the Greeks. Aeneas and the Sibyl pass the section of the Underworld devoted to tormenting the guilty souls, noting diverse methods including whips and a liver-eating vulture.
Even in the land of death, the Greek-Trojan conflict lingers. Here the Greeks come off as cowards. It's comical that the shades are afraid of Aeneas, given that he can't possibly hurt them. The gruesome methods of torture resemble those in Dante's Inferno.
Aeneas leaves the golden bough at the gate to the happy part of the Underworld, the Elysian Fields. He and the Sibyl cross into the beautiful meadows, where the shades enjoy music, dancing, and athletic contests. They see Trojan ancestors and great poets. Aeneas asks one Trojan where he can find Anchises, and the Trojan points them to a ridge where they'll have a better view of the Elysian fields. When they find Anchises, he .joyously greets Aeneas. Aeneas explains that he came specifically to see Anchisees, and tries three times to hug Anchises, but each time the ghost fades away.
It's striking how much the festivities of Book 5 in which Aeneas and his men honored Anchises's death resemble Virgil's version of paradise. The emphasis on culture and the arts (the music, dancing, and poets) also approvingly link the scene to Augustus Caesar, as he was a great patron of the arts in Rome.
Aeneas then notices the souls crowded near a river. Anchises explains that those souls have passed a thousand years in the Underworld, and, finally cleaned of their mortal pasts, they are preparing to re-enter the world in new bodies. He points out Aeneas's descendents, who will be great kings in Italy, and eventually in Rome. Anchises describes Rome's seven hills, and how it will be blessed above all cities and will rule the world. He identifies Augustus Caesar, who will preside over a golden age and describes the greatness of other Roman heroes who will live during Augustus's rule. He then describes the great defining characteristic of Rome: "These will be your arts: to put your stamp on the works and ways of peace, to spare the defeated, break the proud in war." Aeneas asks about a particularly beautiful soul, but Anchises mourns that this soul, Marcellus, a promising nephew of Augustus, will only live a short time on Earth.
This is (debatably) the most important section of the entire Aeneid—the moment when Virgil, via Anchises, defines Roman greatness. If we interpret the poem as a glorification of Rome, this is definitely the thesis statement. The gist is that Romans are better than Greeks (the only similar nation that preceded them) because they know how to spare the conquered and vanquish the arrogant—to defeat those who threaten them, but, once they have defeated them, to spare them and make them a part of their peaceful empire. In addition, this is the moment when Aeneas learns the full measure of his destiny, allowing him to completely accept and pursue his fate.
The time comes for Aeneas to leave the Underworld. There are two exits to the underworld. One is the gate of horn for true shades, and the other is the gate of ivory for false dreams. Anchises escorts Aeneas and the Sibyl to leave through the gate of false dreams.
After such a triumphant description of Rome, it seems bizarre that Aeneas leaves through the gate of false dreams. This is one of the most mysterious and controversial moments of the Aeneid. Is it simply because Aeneas is actually alive, meaning he's not a true shade, that makes him have to leave through that gate? Or is Virgil making a commentary on the political lies of the Empire, the flaws of empire and colonization, and the prideful exaggerations of Roman identity? The question remains a matter of debate.