Patroclus returns to Achilles’ camp, crying with pity for the Achaean losses. Achilles tells him he has no reason to grieve, saying that Agamemnon’s men are “repaid for their offenses.” Patroclus replies that Achilles’ anger is too stubborn. Patroclus asks if he can go into battle in Achilles’ place, wearing Achilles’ armor in order to demoralize the Trojans.
Achilles’ pride and anger toward Agamemnon are extreme, and even the deaths of many of his comrades fails to move him. For Achilles, the preservation of his honor is the measuring stick for his life, and every Achaean injury makes his honor greater, as it will make it all the more impressive when he returns to battle and saves the day.
Achilles initially refuses Patroclus’ request, but ultimately agrees, under the condition that Patroclus will return after he drives the Trojans back from the ships. Achilles remarks that Patroclus should not pursue the Trojans because any glory Patroclus receives beyond the ships might diminish Achilles own glory. Achilles is also concerned for Patroclus’ safety, and worries that a god might appear on the battlefield to intervene.
Achilles does not realize that his acceptance of Patroclus’ proposal helps execute Zeus’ plan. The only thing that matches the intensity of Achilles care for his own glory is his love and concern for Patroclus.
Meanwhile, in the battle for the ships, Great Ajax is finally driven off the ship he is defending. He falls back and the Trojans succeed in setting the ship on fire. Patroclus sees the blaze and quickly puts on Achilles’ armor. Achilles’ chariot is yoked and Achilles stirs up the Myrmidons, his troops. Achilles prays to Zeus, asking him to fill Patroclus with courage and to bring him back safely from battle. Zeus hears his prayer, but decides only to honor half of it, deciding that Patroclus will not return from the battlefield.
The burning of the first Achaean ship is a sign that the Achaeans are in serious trouble. The ancient Greeks were a seafaring people, and made their wealth using their ships. Accordingly, their vessels were precious, and in the case of the Achaeans, their only way to return home. Patroclus, then, enters the battle at a pivotal moment, with the fate of the whole war hanging in the balance.
With Patroclus leading them, the Myrmidons swarm into battle, and are described as being like wasps that a boy has angered. The Trojans, seeing the fresh reinforcements and thinking that Achilles has returned, immediately begin to fear for their lives. Patroclus begins killing Trojans, and the Achaeans drive the Trojans back from the warships. Several Achaean captains kill their opponents.
The Myrmidons have not fought since Achilles’ quarrel with Agamemnon began, and the troops are eager to demonstrate their prowess. Patroclus proves that he is a very strong fighter, capable of winning glory without Achilles’ help, even as he is disguised as Achilles.
The tide of battle turns further, and the Trojans’ orderly retreat turns into a rout. Hector speeds away, but many Trojans are trapped in the Achaean trench. With Patroclus in the lead, the Achaeans slaughter the Trojans in the trench. Patroclus kills every Trojan he encounters. Patroclus faces Sarpedon, a Trojan ally and a son of Zeus, and eventually kills him. Zeus considers saving Sarpedon from Patroclus, but Hera scolds him, telling Zeus not to interfere in Sarpedon’s mortal destiny. As a compromise, Zeus decides to send his body home intact after Patroclus kills him.
Patroclus string of kills is one of largest in the poem so far, and his fury is both an escalation of previous feats and a preparation for the even more miraculous feats of Achilles to come. Sarpedon’s death illustrates Zeus’ inability to master fate, as he is compelled to let his son die despite seeming to have the power to save him. However, his love for Sarpedon allows him to spare his body from desecration, and shows the importance to fathers and families of providing proper respect to the dead—a theme that will return upon the death of Hector.
Glaucus is filled with grief at the death of Sarpedon, his co-commander. Apollo fills Glaucus with strength. He exhorts Hector to remember his Trojan allies, and a battle begins over Sarpedon’s body. The great Trojan and Achaean captains fight for the corpse, and several men are killed on both sides.
Glaucus’ speech demonstrates the high passions experienced at the loss of a close friend in battle, foreshadowing Achilles feelings at the death of Patroclus. Sarpedon’s corpse is a sign of honor: the Trojans look to save it, and the Achaeans look to disgrace it in front of the Trojans.
Zeus briefly deliberates whether to kill Patroclus now in reprisal for Sarpedon, or to let him gain more glory first. He decides on the latter, influencing Hector to call a full Trojan retreat. As the Trojans flee, Patroclus pursues them across the plain, violating his promise to Achilles to return after defending the ships. Patroclus kills more Trojans and nearly storms the gates of Troy. Apollo rebuffs Patroclus, telling him that it is not his fate to seize Troy.
Unbeknownst to Patroclus, his fate is in Zeus’ hands. Despite his sorrow over Sarpedon’s death Zeus decides that it is better to give Patroclus more glory, as it is more in line with Zeus’ original plan. The more that Patroclus distinguishes himself in battle, the more tragic his death will be.
Apollo appears beside Hector in mortal form, and convinces him to attack Patroclus. Patroclus kills Hector’s chariot driver, and Hector and Patroclus fight over the corpse. Fighting for the body, Patroclus charges the Trojans force repeatedly and kills many men, but on his fourth charge Apollo knocks Patroclus over from behind. Sent tumbling, Patroclus is speared by the young Trojan Euphorbus. Hector pounces on Patroclus and finishes the kill. He tells Patroclus that Achilles cannot save him now. With his last breath, Patroclus predicts to Hector that Achilles will kill him.
Patroclus reaches great heights on his rampage, nearly storming Troy, but his demise is less glamorous. Apollo pushes him from behind, and one of the youngest Trojans spears him. There is a sense that Patroclus has overstepped his limits, and that the battle must return to its natural order as decreed by Zeus.