In Book X, with both protagonist and antagonist present for the first time, the war enters its crucial phase. Turnus's killing Pallas will lead eventually to his own death, for Turnus arouses in Aeneas a lust for vengeance that transforms the Trojan leader into an unrelenting enemy. Aeneas's fury will be heightened by the sight of Pallas's swordbelt, which Turnus unceremoniously wears as a war trophy during his battle with Aeneas in Book XII. There, the Trojan hero will dismiss from his mind the fleeting thought of sparing Turnus and will lead him instead to give the final, killing thrust that brings an end to both Turnus's life and the epic poem.
Book X concludes with Aeneas slaying his other great antagonist, Mezentius. This incident is one of the most powerful in the Aeneid and offers an outstanding example of Virgil's ability to introduce, at the very moment of triumph for the victor, a note of pathos that opens us to sympathy for the victim. Virgil's power to awaken this feeling is all the more remarkable because in this case the victim, Mezentius, is monstrous. Although gravely wounded, Mezentius takes on a heroic stature by fighting Aeneas to avenge his son's death and make amends for his own evil past.
In his grief over Lausus, whom Aeneas reluctantly slays, Mezentius resembles Evander, who loses Pallas. The love that exists between fathers and sons — Aeneas and Anchises offer the greatest example — is perhaps the most powerful emotional tie portrayed in the Aeneid and is closely bound up with the ideal of pietas — patriotism and duty.
