Zeus is out, Poseidon is in. Poseidon provides help for the Greek side partly out of a desire to go against his big brother. The intervention is timely for the Greeks, who have been weakening in their fight against Hector and the advancing Trojans.
Nestor speaks to Diomedes, Odysseus and Agamemnon about how the battle is going. Odysseus tells the group that they must return to the battle, even it is just to encourage the soldiers on the ground. Hera seduces Zeus and puts him into an enchanted sleep to distract him from the Greeks gaining Poseidon's favour.
We need to go back to the Battlefield
Zeus wakes and sees the havoc that Hera and Poseidon have wreaked while he dozed in his enchanted sleep. Hera tries to blame Poseidon, but Zeus comforts her by making clear that he has no personal interest in a Trojan victory over the Achaeans. Poseidon is ordered to leave the battlefield.
Patrokolos takes Achilles armour and leads the greeks in an attack against the Trojans. He dies in this battle.
Menelaos gets in a fight with Euphorbos—the first man to spear Patroklos in Book 16—over Patroklos's body.Menelaos kills Euphorbos and starts stripping off his gear, but then backs down in the face of stronger Trojan numbers.
Glaukos: We should capture Patroklos's body and then use it as leverage to ransom back Sarpedon's body and his armor from the Achaians.
Achilleus learns of Patroklos' death, and Thetis, his mother, consoles him. He wants to join the battle, but Thetis reminds him that he has no armor. She promises to get new armor from Hephaistos, the smith of the gods. Achilleus' warcry drives the Trojans away, and the Greeks finally recover Patroklos' body.