When authors refer to other great works, people, and events, it’s usually not accidental. Put on your super-sleuth hat and figure out why.
Homer's Iliad. Like most sequels, Odyssey is full events and people detailed in Homer's earlier poem, like Achilleus (3.114), the Trojan horse (8.533-558), Helen (23.246-252), and Agamemnon (24.16-111). Intrigued? Go read The Iliad, already!