Homer begins by asking the Muse, the goddess of poetry and music, to sing to him about Odysseus and his travels. Odysseus and his crew have seen many strange lands and have suffered many trials. Their careless behavior has sometimes angered the gods, who have prevented their safe return to Ithaca.
Like The Iliad, The Odyssey begins with a prayer to the Muse: the poet is a vessel for the goddess's song. We learn that some combination of human error and divine will has delayed Odysseus's and his crew's homecoming.
"Start where you will," says the bard to the muse, and so the story begins in the middle of Odysseus's long journey home from Troy. The nymph Calypso has held Odysseus captive for seven years on the island Ogygia, and the goddess Athena has come before an assembly of the gods to plead for his release. Odysseus angered the sea god Poseidon, who has been hindering Odysseus's return to his home in Ithaca. Zeus declares that Poseidon must forget his grievance and agrees to send the messenger god Hermes to Ogygia to ensure Odysseus's release from captivity.
We learn that Athena favors Odysseus, for some reason, and has made it her mission to ensure his safe return. Odysseus's fate hangs on Zeus's decision – will Zeus respect Poseidon's anger or overrule it? Zeus decides to spare Odysseus and sends Hermes to order Calypso to release Odysseus from captivity: here, the gods interfere directly with Odysseus's life.
Meanwhile, Athena flies to Ithaca to speak to Odysseus's son Telemachus. Droves of men courting Odysseus's wife Penelope have been feasting for years in Odysseus's court, pestering Penelope and depleting the resources of the estate. Athena takes the shape of Mentes, a friend of Odysseus's father Laertes. She finds Telemachus sitting idly in the midst of the festivities, dreaming of routing the insolent suitors from the estate.
Athena usually takes human form in her interactions with Telemachus, perhaps in order to make her divine interventions less conspicuous. The suitors dishonor the house by insulting Penelope and stealing Odysseus's property, so Telemachus feels that it's his duty to stop them: it is honorable to stop a dishonorable act.
After Telemachus has given Athena a proper welcome, she tells Telemachus that Odysseus is still alive, and that he is held captive on a faraway island. She prophesies that Odysseus will soon return to his home. Telemachus describes the shame the suitors have brought upon the estate. Athena advises that he gather a crew and sail to Pylos and then to Sparta in search of information about Odysseus. She tells Telemachus that he must avenge his father by killing the suitors that dishonor the estate, as Prince Orestes avenged the death of his father Agamemnon by killing his father's murderer. Telemachus thanks the stranger for the kind advice; his memory of Odysseus grows vivid and his strength increases, and he thinks that the stranger must have been a god.
Telemachus carefully follows the customs of hospitality: he gives the stranger food and drink before asking his name. His conversation with Athena invigorates him, but in what way? Does he simply feel encouraged by a stranger's prophecy and good advice, or by a god's protection? Or does Athena magically grant him increased strength and confidence? Athena confirms Telemachus's sense that it is his duty to drive out the suitors. The memory of Odysseus strengthens Telemachus's resolve to take action.
Penelope comes down from her chambers and asks the bard entertaining the suitors to stop singing about the Achaeans' journey home, because the song brings her too much grief. Telemachus reproaches her; he reminds her that Zeus, not the bard, is responsible for Odysseus's suffering. He tells her to have courage, to listen to the bard's song, and to remember her husband. Penelope obeys him, surprised by his good sense and strong will.
Telemachus's conversation with Athena has transformed him – he reproaches his mother for the same kind of moping he was engaging in earlier, and reminds her that memory can be a source of strength, not just a cause of grief. He tells her not to blame men for something that is the will of the gods, thus shows respect to the gods.
After Athena flies away, Telemachus addresses the suitors. He tells them to leave his household at once, or Zeus, the god of hospitality, will punish them for their wrongdoings. He declares his intentions to remain the lord of the estate in Odysseus's absence. The suitors are amazed at the prince's confidence and daring. Antinous responds that only the gods could give Telemachus the power to speak so courageously. Eurymachus adds that the gods alone decide who will rule Ithaca, and inquires about the strange visitor. Telemachus replies that the visitor was Mentes, a friend of Laertes, but he knows in his heart that the visitor was the goddess Athena.
Telemachus knows now that Athena shares his sense of right and wrong – of honor and dishonor – and so he addresses the suitors with great conviction. He threatens them with the vengeance of the gods: men and gods both punish wrongdoings. The suitors try to belittle Telemachus by implying that he's only a pawn of the gods rather than a man with a will of his own. Telemachus displays cunning in hiding Athena's real identity from the suitors.