The Iliad: Book I

The story begins with Chryses, an Apollonian priest, begs to have his daughter, Chryseis, back from Agamemnon, an Achean leader, who took her as a "spoils of war". Chyrses was denied and forcefully driven out of Agamemnon's presence. Chryses prayed to Apollo, his patron god, and Apollo strode down Olympus and began killing the Acheans through a great sickness. Achilles, a prominent soldier of the Acheans, called an assembly among the army, asking also for a soothsayer to figure out why people were dying. Calchas comes to Achilles and reveals the plague as a revenge tactic of Chryses via Apollo. Agamemnon is enraged, but refuses to give back Chryseis unless he has compensation, which is concluded to be Briseis. Achilles is offended by the taking of Briseis, and threatens to leave the Achean army. He later confronts Agamemnon, threatening his life. Before Achilles gives Agamemnon an assumably fatal strike, Athena comes down to him and puts reason in his actions. The story ends on Olympus, where Zeus and Hera argue over which of the sides (of the battle) shall win. They are soon loosed from anger with "nectar", as they all fall asleep.

A definite theme in The Iliad is replacement for lost things, as well as the idea of vengeance. Apollo strikes Agamemnon, Agamemnon loses something valuable; he must replace it with something more valuable, Briseis; and Achilles is the one in loss, and he must continue to shift the loss to someone else, and so on. 

A prominent line in Book I is in line 136-139 "What I [Agamemnon] really want is to keep my people safe, not seeing them dying. But fetch me another prize, and straight off too, else I alone of the Argives go without my honour." This text only speaks to the idea of replacement in the Iliad, as it also shows the innocence of Agamemnon. He is not a man who likes to do harm, but to keep people safe. He feels like the only way to keep his people safe is by keeping his honour, by taking all of these "spoils of war".