Let's begin by thinking about what we have discovered in the first twelve books of Homer's Iliad. For one thing, we discover the reasons behind the Trojan War. Paris of Troy has made off with Helen, wife of Menelaus of the Achaeans. This sets the stage for the conflict. But the poem does not open with this conflict. Rather, it opens with a conflict between Achilles and Agamemnon. Achilles is angry and pouting because he is being forced to give back the woman he won as a prize of war, and he refuses to fight with the Achaeans any longer. He will sit out this war, he declares.
Yet the war rages without Achilles, and we learn all about the extreme courage of the warriors on both sides. As the fighting goes on, the Achaeans end up on the losing end even though they fight bravely. Many of the them are wounded, and the Trojans keep pushing onward. We can see that both sides desperately want to win this fight. The Trojans are trying to defend their city, and the Achaeans long for glory and vengeance. As the Trojans advance, several Achaeans, including the valiant and wily Odysseus, visit Achilles and urge him to help, yet he says he will not, at least not until he is personally threatened. We also learn some about the women of Troy who bravely stand behind their husbands and sons.
The gods are also deeply involved in this war, and they have plenty of conflicts of their own. Apollo, for instance, is angry at the Achaeans because the woman kidnapped by Achilles is the daughter of one of his priests. Zeus decides to help the Trojans, while Hera takes the Achaean side. Athena also supports the Achaeans, while Aphrodite prefers the Trojans. Eventually Zeus tells all the immortals to keep their noses out of the war. Things are getting out of hand. But when the Achaeans are pushed back to their ships, Poseidon can't stand it, and he heads back into battle.
We might think that by the end of book 12, the story may be ready to take a turn one way or another. We have reached the middle of the tale, and there is a precarious balance that cannot last. The battle is still raging, but the gods have gotten involved once again. Further, Achilles seems to be on the brink of reentering the war, and we might wonder what will happen if he does. We might even expect that the Achaeans, with Poseidon's help, will push back against the Trojans and begin to get the upper hand, especially if Achilles joins in. Keep on reading to find out what happens next.