With the combined Trojan and Etruscan forces at Laurentum's gates, Turnus becomes fully aware that the Latins are in grave danger, so he renews the offer he made earlier in the citadel before Latinus and Drancës: He will fight Aeneas alone, and the winner will have Lavinia for his wife.
Both Latinus and Amata try to dissuade Turnus from this resolution, which they recognize as foolhardy, but Turnus stubbornly sticks to his decision and sends his herald to inform Aeneas that both sides are to join in a truce, and that he and Aeneas will fight the next day at dawn. That night, Turnus inspects his horses and his armor, whetting his appetite for battle, while Aeneas, equally aroused, rejoices in the armor that Vulcan made for him at his mother's request.
At dawn, the two armies meet on a plain near the city. Juno, however, fearful for Turnus, summons Turnus's sister, the river nymph Juturna, and bids her to go to her brother's aid, either to save him from death or to break the truce. On the plain, sacred rites are performed, and Aeneas vows to the gods that if Turnus wins the fight, the Trojans will withdraw to Pallanteum and no descendants will ever attack the Latins in the future. He promises that if he should win, he will claim nothing for himself: The Latins and the Trojans will live together peacefully as equals; he will marry Lavinia; and her father, Latinus, will retain his power. Latinus solemnly agrees to these terms and declares that from this time on there will be peace.
The Rutulians, however, are discontented. Juturna, moving among them disguised as one of their nobles, takes advantage of the Rutulians's restless mood: Because they outnumber their opponents two to one, she declares, they should be ashamed to let one man do the fighting for all of them. Angered, the Rutulians are ready to break the truce. At this moment, a pack of waterfowl dive and threaten an eagle that has seized a swan; when the eagle releases the swan, the Rutulians take this act as a portent signifying that they, too, will be victorious if they resist Aeneas. They are encouraged by an augur, a priest adept at reading bird omens, who hurls his spear at the Trojans and thus initiates a resumption of hostilities.
Aeneas, who vainly attempts to restore the broken peace, is wounded by an arrow and forced to leave the field. His withdrawal raises Turnus's fighting spirit to the point that Turnus goes mad with bloodlust and kills as many opponents as he can reach. Meanwhile, Venus heals Aeneas with a magic herb: The enemy arrow drops from his wound, and his strength is miraculously restored.
Returning to the field, Aeneas rallies his forces and goes in pursuit of Turnus. Juturna, meanwhile, who has cleverly taken control of her brother's chariot by disguising herself as its driver, drives Turnus all over the field, keeping him safe from an attack by Aeneas, who goes wild with frustration and, like Turnus, kills without stint. Venus now directs her son's attention to the fact that Laurentum's citadel has been left undefended by the Latins, whereupon Aeneas commands his men to attack it immediately, to the horror of the citadel's Latin inhabitants. Fearing that all is lost and that Turnus is dead, Amata hangs herself in despair.
On the battlefield, Turnus hears cries coming from the besieged citadel and tells Juturna that he has finally seen through her disguise as his charioteer. At this point, a warrior coming in haste from Laurentum informs Turnus about what has been happening in the city and announces the queen's death. He mockingly points out that Turnus, the famous warrior, has been driving over an empty meadow — a fact to which Turnus now fully awakens, filled with remorse. Turnus tells Juturna that now he will fight Aeneas alone, as he promised earlier.
Turnus and Aeneas meet outside Laurentum, and the long-awaited battle takes place. Full of confidence, the Rutulian strikes the Trojan with his sword, which is not his own powerful weapon but one belonging to his original chariot driver, taken by mistake. The sword shatters immediately upon contact with Aeneas's armor. Calling on his men to bring him his proper sword, Turnus withdraws as Aeneas pursues him. The Trojan prince hurls his spear at the Rutulian prince, but the spear gets immovably lodged in the trunk of a sacred olive tree in answer to Turnus's prayer to the god Faunus. Juturna brings her brother his true sword, but Venus intervenes and enables Aeneas to extricate his spear.
The duel continues, watched by Jupiter and Juno from a golden cloud. Jupiter tells Juno that Aeneas is about to win and that she can do nothing more to hinder him. Juno promises to cease her opposition to the Trojans, but she asks her husband to permit the Latins to retain both their language and their name. Jupiter grants these requests and tells Juno that out of this alliance of Latins and Trojans will come an indomitable race — the epic's final prophecy, which matches the one Jupiter made to Venus in Book I.
Jupiter now sends a fury to earth disguised as an owl, which darts at Turnus and fills him with terror. Juturna withdraws in discouragement, realizing her helplessness in the face of such an omen. Aeneas advances at Turnus with his spear as the Rutulian, making a last, desperate effort, heaves an enormous rock at Aeneas. The rock falls short, and Turnus, paralyzed by fear, is knocked down by Aeneas's spear, which strikes him in the thigh. Helpless, Turnus says he is resigned to dying, but he begs Aeneas to see that his body is returned to his father. Moved by this plea, Aeneas considers sparing Turnus's life, but then he sees that the dying warrior is wearing Pallas's swordbelt as a trophy. This reminder that Turnus killed Aeneas's dear friend arouses the Trojan hero's anger, and he remorselessly thrusts his sword into Turnus's chest, killing him.
The tragic, somber, final line of the Aeneid and the epic poem's ringing, declamatory opening line signify the two emotional poles of the epic. Their positioning has a symbolic as well as a narrative importance, for between the moods to which they give voice, the poem constantly moves back and forth as it unfolds. The establishment of Rome is achieved only through the human suffering of Aeneas and his people, and of his opponents — Dido in the first half of the epic, and now, at the end, Turnus.
Virgil's vision of reality was too honest to allow him to see life other than as a mixture of good and evil elements. Had Virgil been merely a propagandist for Augustus, he might easily have finished the epic on a triumphant note. For example, he could have concluded it with the conversation between Jupiter and Juno in this final book, with the king of the gods assuring his consort of a glorious future for the Romans, whose protector she would happily become.
Instead, Virgil gives the epic's final line to the last moment in Turnus's life, the moment that marks the utter, hopeless defeat of a man who is stripped of his glory and virility and becomes a moaning ghost. Aeneas's victory is complete, but it must be paid for by the downfall of a worthy enemy, for whom nothing remains but a retreat into the shadows of the underworld.
The epic's final lines, "And with a groan for that indignity / His spirit fled into the gloom below," are the same that, in the preceding book, described Camilla's death. The repetition reinforces the likeness between Camilla and Turnus, friends and allies in a battle for a lost cause, both cut down in the prime of their youth.
Turnus's fate, however, unlike Camilla's, is mitigated by his inability to control his emotional rage. This lack of control reaches its height in Book XII, which we expect since the book details the final conflict between Turnus and Aeneas. The rage Turnus felt at the end of Book XI carries over to the beginning of Book XII, in which his passion is described as "hot and unquenchable." Virgil, as he did earlier with Dido, associates Turnus's intense feelings with fire. The uncontrollable lust that consumes the Carthaginian queen is similar to Turnus's overwhelming craving for Lavinia: "Desire stung the young man as he gazed, / Rapt, at the girl. He burned yet more for battle." The greater Turnus's passion for Lavinia, the greater his wanting to do battle, yet his military judgment is clouded by his passion for the young princess. As Virgil notes of Turnus toward the poem's end, "He did not know himself. His knees gave way, / His blood ran cold and froze."
Surprisingly, Turnus redeems himself — at least partly — when he finally accepts that it is not his fate to win against Aeneas. We sympathize with Turnus's plight, especially when, speaking resignedly to his sister, he acknowledges the ignoble afterlife that awaits him. His speech to her is notable for its timeless questioning of what death holds for all of us: "To die — is that / So miserable?" Ultimately, Turnus's greatest fear is not dying; his greatest concerns are the opinions that others will have of him after he is dead and, as with all of the other warriors in the poem, how his reputation will affect his family's good name.
Aeneas, who wants nothing more than to end the war, rouses himself to battle as passionately as his antagonist does, but Aeneas's reasons for wanting to do battle are radically different from Turnus's. Aeneas understands that by fighting Turnus one on one, only he or the Rutulian will die, and not the many warriors who would were the all-out war to continue. Even when large-scale battle again breaks out, Aeneas does not kill any of his enemies; instead, he seeks Turnus exclusively, knowing that if the renegade warrior is killed, then his followers will cease fighting. As Aeneas tells Latinus, he wants no kingdom for himself. His only goal, as it has been throughout the entire epic, is to build a city in which he and his displaced countrymen can settle peacefully.
The fight that finally ensues between Aeneas and Turnus is described as earth-shattering. After all, the fate of the civilized world hangs in the balance. Virgil emphasizes the universal importance of the battle when he writes that the earth groaned from the crashing of the warriors's shields. Even more cataclysmic is the groan "heard echoing on all sides from all / The mountain range, and echoed by the forests" when the Rutulians realize their leader has fallen. The epic poem has been leading up to this grand finale, and every detail here at its end furthers the sheer magnificence of the founding of Western civilization's greatest empire.