Zeus sends the goddess Hate down to rouse the Achaians for battle.
Agamemnon starts things rolling.
Now Zeus sends panic among the troops, and makes the heavens rain blood. Yikes.
Hate is the only god taking part in this battle, but Zeus is watching from above.
When the fight begins, Agamemnon kills various dudes—including some who are begging for mercy.
The Trojans start fleeing toward Troy, with Agamemnon in pursuit.
Seeing this, Zeus sends a message down to Hektor via Iris. He tells Hektor that, as long as Agamemnon is going berserk, he and the Trojans should fight defensively. That said, as soon as they see Agamemnon get wounded, they have Zeus's permission to get Bronze Age on his hiney.
After Iris delivers this message, Hektor gets the Trojans into defensive battle lines.
The Achaians keep coming at them hard.
The poet asks the muse to help him remember all the dudes that Agamemnon fought with—he is killing that many.
Before killing one guy—Koon—Agamemnon receives a stab in the forearm. He keeps fighting for a while, but eventually realizes he has to go back to the ships.
When Hektor sees this, he calls on his soldiers to really give it to the Achaians.
Hektor kills various Achaian warriors.
Seeing this, Odysseus shouts out to Diomedes, his new partner in crime (see the summary of Book 10) and asks him, "Why aren't we stopping this guy?"
Odysseus and Diomedes lead a counterattack and kill various Trojan warriors.
Finally, Hektor comes bearing down upon Odysseus and Diomedes. Although they are frightened, they don't back down.
Diomedes throws his spear and hits Hektor in the head—but it deflects off his helmet!
Hektor withdraws to a safer spot and braces himself while he briefly blacks out. Then he regains consciousness: he's okay.
The fighting rages on.
Then, suddenly, Paris hits Diomedes in the foot with an arrow. He starts taunting his victim, but Diomedes calls him a wuss for fighting with a bow from far away.
Then Diomedes pulls out the arrow and gets his charioteer to take him back to the ships.
Now Odysseus is left without any other Achaians around him. In an instant, he is surrounded by Trojans. He fights them off (i.e., kills them all) but is wounded.
When a second round of Trojans encircles him, things are looking bad. He starts calling out for help.
Menelaos and Aias hear him and come to his aid. Together, they defeat that group of Trojans.
The fighting rages on. Eventually, the Achaians start to get forced back.
Hektor is partly responsible for giving the Trojans the upper hand. Part of the credit also goes to Paris, who shoots Machaon, the Achaian healer, in the shoulder. This makes the Achaians scared.
To get him out of harm's way, Nestor puts Machaon in his chariot and takes him back to the ships.
The next Achaian warrior to have to hold his own against a large number of adversaries is Aias— that is, until a group of Achaians comes to help him out.
Meanwhile, Nestor and Machaon arrive back at the Achaian camp.
Achilleus, who has been watching the battle from the stern of his beached ship, sees them go by.
He calls Patroklos out of his tent to double-check that it really was Machaon.
Patroklos obeys—and, the poet tells us, in that instant his doom is sealed.
When Patroklos gets to where Nestor and Machaon are and confirms the injured man's identity, he turns to go.
But Nestor holds him back, and spells out for him just how much kitty litter is hitting the fan out there. He says that he wishes he were able to help and then—you guessed it—tells a long story about how awesome he was back in the day.
Then Nestor tells Patroklos about the day he and Odysseus came to the house of Peleus looking for recruits. He reminds him how eager he and his playmate Achilleus were to join the expedition.
Nestor also reminds him of the advice their fathers gave them: how Achilleus's father, Peleus, told his son always to be the best warrior. But Menoitios, the father of Patroklos, told him that his role was to give good advice. "Even though Achilleus is stronger," Menoitios said back then, "you are older and wiser."
Now Nestor gets to the point. He suggests that Patroklos should lead the Myrmidons—these are the tribe of warriors that follow Achilleus—into battle. Maybe he could even wear Achilleus's armor, to strike terror into the hearts of the Trojans.
Patroklos is thrilled by this suggestion and runs off to find Achilleus.
Along the way, he encounters the Achaian warrior Eurypylos, who has been injured by an arrow.
Eurypylos gives Patroklos even more of the bad news on how they're doing.
Patroklos helps Eurypylos back to his tent and removes the arrow.