Apollo is the Greek god of the sun, music, and poetry and is associated with archery as well in Homer's Odyssey. When the Greeks, including Odysseus, were pillaging near Troy at the start of the Trojan War, as recounted in Homer's Iliad, Agamemnon seized the daughter of the priest of Apollo as a war prize. This offended Apollo, who sent a plague against the Greek army, which he only lifted when the war prize was returned. Throughout the Trojan War, Apollo supported the Trojans against the Greeks. Apollo does not actually make an appearance in the Odyssey, although the archery contest which is part of Odysseus' stratagem to rid himself of the suitors and regain his rightful place in Ithaca does take place during Apollo's feast day. Odysseus also in his travels recounts some of the stories of the Trojan War treated in more detail in the Iliad.
Two unpleasant places, the realm of Hades and Polyphemus' cave, are portrayed as shrouded in darkness, and the people (dead or alive) trapped in them as longing to return to the light.