Chryses comes forward to Agamemnon to beg for his daughter Chryseis, whom he had captured. Agamemnon refuses, leading to Apollo to intervene and cast a plague upon the Greek army. The plague wipes out a considerable number of men, and eventually Achilles gathers an assembly to assess the problem. After much feuding Agamemnon agrees to return Chryseis, but he exchanges her for Achilles's daughter Briseis instead. Angered, Achilles leaves the army.
Without Achilles's help, the Greek army suffers. Hector, the son of Priam, leads the Trojans and battles fiercely against the Greeks. Agamemnon, who realizes his wrongdoings, attempts to reconcile with Achilles and his comrades. He sends his ambassadors to offer gifts to Achilles, but he flatly refuses. It is only when his closest friend Patroclus convinces him to rejoin that he comes back. During one battle, Apollo strikes Patroclus, allowing Hector to kill him. Enraged and overcome with grief, Achilles vows to avenge his friend, and he returns to mercilessly slay the Trojan Army.
Achilles stands in front of the Trojan walls, clad in a brilliant armor made by Athena. The Greeks and Trojans engage in an epic battle against each other that wages on, until Apollo appears as himself to the soldiers. Everyone retreats except for Hector and Achilles, who are now at a face-off. Hector loses his wits and starts to run away; Achilles gives chase. Achilles pursues Hector closely, but the chase lasts for a drawn-out period of time. Finally, Athena disguises herself as Hector's brother Deiphobus, and she tricks him to face Achilles. Hector attacks Achilles but fails to strike him, and he realizes Deiphobus was a trick by the gods. Hector realizes his inevitable death, and he boldly attempts to slay Achilles. Achilles kills Hector.
Achilles, overcome with pride, dishonors Hector's corpse. The ghost of Patroclus emerges to Achilles in a dream and urges the burial of Hector's body. Confounded by this atrocity, Zeus decides that Hector's body must be returned to Priam. Led by Hermes, Priam begs for Hector's body from Achilles. He plays with Achilles's emotions and mentions the demise of his father and the losses of the war. The two mourn over the war, and after a meal, Hector's body is buried, and the city mourns over him.