Achilleus pins the Trojans against the River Xanthos (not to be confused with Achilleus's horse of the same name. The river is also known as Skamandros).
There, he drives half of them toward the city; the other half he pushes into the river itself.
Then he dives in and starts furiously killing people, staining the water red with blood.
After he's had his fill of that, he grabs twelve young Trojans, hauls them up on the bank, and ties them up. Then he gives them to some friends of his to take back to the ships as prisoners.
At this point, he sees crawling up onto the bank someone he recognizes—Lykaon, a son of Priam. Some time earlier, Achilleus had captured Lykaon and sold him into slavery. As it turns out, though, someone ransomed him, and he has now been back in Troy eleven days.
Achilleus throws his spear at Lykaon, but Lykaon dodges it and grabs Achilleus's knees, begging for mercy.
Achilleus makes a fearsome speech, saying, "No way. But don't worry. I'll die soon too, so it's all okay." Then he kills Lykaon with his sword and throws him into the river.
Achilleus mocks Lykaon because the river will take him far out to sea, so no one will ever bury him.
This makes the river angry. (Yes, you heard that right. The Ancients thought of rivers as gods.) For the moment, though, nothing comes of it.
Next Achilleus gets in a fight with another Trojan, Asteropaios.
Asteropaios boasts of his ancestry, and how he was the son of the River Axios.
Achilleus says, "Big deal. My great-grandfather is Zeus."
Achilleus kills Asteropaios and throws his body in the River Skamandros.
Now Skamandros is really angry. He tells Achilleus to stop clogging his water with dead Trojans.
In reply, Achilleus says, "Fine. But I'm still going to keep killing lots of Trojans."
At that, Skamandros goes off and complains to Apollo. He asks him to protect the Trojans until the sun goes down.
When Achilleus hears this, however, he gets angrier than before—so angry, in fact, that he jumps into the river and starts attacking it.
Alright, so, as you could probably have guessed, fighting a river is not a good idea.
Soon enough, Achilleus is running across the plain with the river chasing after him, sometimes curling up into huge waves and trying to crash on his head.
Understandably, Achilleus prays for help. Poseidon and Athene come down and reassure him that it isn't his fate to be killed by the river. They also tell him that, once he's killed Hektor, he shouldn't continue on to capture Troy. Instead, he should head back to the ships.
When the two gods leave, however, Achilleus's battle with the river continues.
In fact, it starts looking like it's about to get a lot worse—because now Skamandros calls on his brother, Simoeis (the other river crossing the Trojan plain), to come help him out.
Just when it looks like Achilleus is about to play his last round of two-on-one, however, Hera calls on Hephaistos, god of fire, to come help him.
Hephaistos's solution is to set fire to all the corpses on the field—thus making a vast wall of flame to contain the two rivers within their banks. He also sets fire to all the plants along those banks, just to make sure.
Soon enough, Skamandros promises he won't make any further effort to save the Trojans from disaster.
At this point Hera calls off Hephaistos.
Meanwhile, the gods are joining the battle.
Ares stabs at Athene, but fails to pierce her divine shield.
In revenge, however, Athene picks up a huge rock and hurls it at him. She hits him in the neck and knocks him onto the ground.
Then, when Aphrodite comes and starts leading Ares out of the battle, Athene runs up to her and starts punching her breasts.
Both Ares and Aphrodite collapse.
Now Poseidon comes up against Apollo. He asks him why he's fighting for the Trojans. He reminds Apollo of some backstory—which we haven't heard until now. You ready for this?
Here's the deal. Apparently, many, many years ago, Zeus compelled Poseidon and Apollo to spend one year as slaves for the Trojan King Laomedon—the father of Priam.
Apollo's job was to herd all the sheep on Mount Ida. Poseidon's was to build the wall of Troy.
As if that wasn't bad enough, when the year was up, Laomedon refused to pay them and sent them packing. That's the end of Poseidon's story.
Poseidon says he can't believe that Apollo would help out the Trojans after having been their slave.
Apollo doesn't answer Poseidon's question; he says, "I'm not fighting you. You're too tough."
Don't worry, you're not the only one who finds this kind of lame. So does the goddess Artemis, Apollo's sister, who starts taunting him and calling him a coward.
But then Hera cusses her out and boxes her ears, making her drop her bow and arrows.
When Artemis arrives back on Mount Olympos, she complains to Zeus about what happened. He doesn't do anything about it.
In any case, all the other gods now withdraw from the battle and reassemble on the holy mountain.
Meanwhile, Achilleus keeps killing lots of guys on the plain. Then, he drives the survivors in the direction of the city.
On the ramparts, Priam is horrified. He commands that the city's gates be opened.
At this point, Achilleus might have burst in and captured the city, if it weren't for Apollo, who instilled strength into the Trojan hero Agenor.
Agenor stands in front of the walls and challenges Achilleus.
He throws his spear and hits Achilleus in the shin, but his armor deflects it.
When Achilleus goes to kill him, however, Apollo carries Agenor away (funny how that happens), and then takes on his form.
The disguised Apollo then leads Achilleus on a wild goose chase over the plain of Troy. This distraction gives the other Trojans enough time to get into the city.