Achilles pursues the Trojans to the ford of the river Xanthus. The Trojan force has split in half: one group runs back to Troy, while the other group tries to cross the river to escape Achilles. The Trojans are described as being like locusts fleeing a fire. Achilles rushes into the water, slaughtering many Trojans in the river. Achilles grows so tired from killing Trojans that he takes twelve young Trojans alive.
The river provides a perfect setting for Achilles’ feats of heroism, slowing the movement of the Trojans as Achilles attacks. Furthermore, the river’s flow is dynamic, mirroring the way in which Achilles swiftly dispatches his enemies.
Achilles also comes across Priam’s son Lycaon, who Achilles had previously captured and sold into slavery. Lycaon managed to return back to Troy, and had only been home for twelve days before running into Achilles again. Achilles, with irony, calls Lycaon’s return from slavery a miracle. Lycaon begs for his life again, but Achilles has no mercy, saying, “Come, friend, you too must die. Why moan about it so?” Achilles kills Lycaon.
The story of Lycaon’s return and death underscores uncertainty of death. Lycaon’s return from slavery was a product of great effort and good fortune, turned suddenly into bad. Achilles’ statement that all men must die also refers to himself. Earlier he took Lycaon alive, but now, knowing he himself must also die, Achilles is different and has no mercy for anyone.
Achilles continues killing Trojans in the river, clogging the stream with blood and bodies. Xanthus, the god of the river, takes the form of a man and asks Achilles to stop killing Trojans in the river. Achilles agrees to stop fighting in the river, but not to stop killing Trojans. Xanthus, angered by Achilles’ resistance, calls on Apollo for help. Achilles is enraged by Xanthus’ interference and plunges into the river to kill more Trojans.
Xanthus protest to Achilles is a sign of Achilles’ immense power: Achilles has killed so many men that his actions are beginning to upset the natural order of things as represented by the river. The fact that Achilles disobeys a god also heightens the sense of Achilles’ glory, as he seems to perform more like an equal of the gods than like a mortal man.
Xanthus flings the corpses out of his river while saving the Trojans still living. Achilles begins to fight the river, and Xanthus creates enormous waves to drown Achilles. Achilles runs ever higher up the embankment, trying to escape the river, but Xanthus nearly pulls him down to his death.
Although Achilles’ strength is nearly supernatural, it is still not enough to defeat an immortal god. Achilles may be nearly immortal, but he is still ultimately a subject to the forces of nature.
Achilles laments that if the river kills him, he will never gain the honor he desires. Poseidon and Athena reassure Achilles. They tell him that he must keep fighting until he kills Hector, and that afterward he must return to the ships. Xanthus calls to the river Simois to help him drown Achilles, but Hera intervenes, calling her son Hephaestus to battle the river with his fire. Under his blaze, the river boils until Xanthus promises to submit.
Achilles is obsessed with gaining as much glory as he can in the day’s battle, but Poseidon and Athena demarcate the extent of Achilles’ success. Achilles’ fame has limits: he is not destined to overpower the city of Troy itself. In addition, he still needs the help of Hephaestus to counter Xanthus.
The gods begin to fight among themselves. Ares charges Athena, but Athena quickly beats down his challenge, striking him with a stone. Athena then attacks Aphrodite, who retreats immediately alongside Ares. Poseidon tries to goad Apollo into battle, but Apollo refuses to fight, insisting that he will not fight over mortals. Apollo’s sister Artemis calls him a coward, and Hera, overhearing Artemis’ taunt, boxes the goddess’ ears. Artemis and her mother Leto withdraw from the battle, and Artemis complains to Zeus about her harsh treatment from Hera.
The engagement of all the gods in battle demonstrates that the poem is moving toward its climax. All the gods are arrayed against one another, making the battle a conflict both on earth and in the heavens. Notice how Aphrodite flees from battle much as Paris does; and it is Aphrodite and Paris who set this war in motion.
Priam watches the carnage wrought by Achilles from the gates of Troy. He orders that the Trojan gates be opened in order let the routed troops back into the city. Apollo looks to distract Achilles long enough to allow the Trojans to escape. Apollo puts courage into the heart of the Trojan prince Agenor. Agenor stands against Achilles but cannot pierce his godly armor. When Achilles attacks, Apollo lifts Agenor to safety and takes his place. He runs from Achilles, creating a decoy that allows other Trojans to escape.
Apollo’s distraction is necessary to prevent Achilles from killing many more Trojans. Apollo can only give a limited amount of help to the Trojans, as he cannot directly disobey Zeus’ plan to give glory to Achilles. However, he does his best to thwart Achilles, attempting to diminish the magnitude of his feats on the battlefield.