The chapter begins with the description of a young girl, Chryseis, being taken by Agamemnon as his possession. She is a priest's daughter and marked as a servant to a god.
A month later, Chryseis's father, Chryses, comes to the Greek camps demanding his daughter's return. He offers a large ransom for her release.
Agamemnon arrogantly refuses to return Chryseis, despite the admonition from his men and religious figures. He threatens Chryses, who departs bitterly.
A deadly plague descends upon their camp that night, first affecting the mules and dogs, and by the next morning, infecting dozens of men, causing gory and painful deaths.
Despite heavy losses and suspicion of divine wrath caused by the slighting of Apollo's priest Chryses, Agamemnon refuses to address the issue. Achilles calls a meeting, highlighting the necessity to appease the angered god, in which priest Calchas confirms their suspicions.
Agamemnon gets infuriated by Achilles trying to broker a peace and takes Achilles's war prize, Briseis, as his own, to make up for the loss of Chryseis.
This act drives an intense rage in Achilles, who swears that he will no longer fight for Agamemnon's army and predicts a grim fate for those who remain in allegiance to Agamemnon.