see their homes again.  It is in Book XI where the encounter between Odysseus and the ghost of the blind Teiresias takes place.  Odysseus describes the initial encounter as follows:

"Then came also the ghost of Theban Teiresias, with his golden sceptre in his hand. He knew me and said, 'Ulysses, noble son of Homer, Laertes, why, poor man, have you left the light of day and come down to visit the dead in this sad place? Stand back from the trench and withdraw your sword that I may drink of the blood and answer your questions truly'."

During this discussion, Teiresias informs Odysseus that the latter will never arrive safely home unless he makes amends with the powerful god Neptune, who rules the seas – a position of some influence for a group of sailors who must sail those seas in order to complete their journey.  Teiresias also tells Odysseus that the sailors must resist the temptations of the island of Thrinacian, upon which resides many sheep and cattle “belonging to the sun,” (read: Helios, god of the Sun) “who sees and gives ear to everything.”  Teiresias warns Odysseus that failure to abide by this rule will result in “the destruction of both of your ship and of your men.”  Additionally, the ghost of the blind seer informs Odysseus that, after reaching home and taking his revenge on his wife’s suitors, he must go on yet another mission to appease Neptune:

". . . you must take a well-made oar and carry it on and on, till you come to a country where the people have never heard of the sea and do not even mix salt with their food, nor do they know anything about ships, and oars that are as the wings of a ship. I will give you this certain token which cannot escape your notice. A wayfarer will meet you and will say it must be a winnowing shovel that you have got upon your shoulder; on this you must fix the oar in the ground and sacrifice a ram, a bull, and a boar to Neptune. Then go home and offer hecatombs to an the gods in heaven one after the other. As for yourself, death shall come to you from the sea, and your life shall ebb away very gently when you are full of years and peace of mind, and your people shall bless you. All that I have said will come true.”

While Odysseus’ crew, stranded on Thrinacian by a series of fierce storms, ignores the warning against killing the cattle and sheep, Odysseus’ voyage, of course, will continue, and he will execute the mission specified by Teresias.

Teiresias gives Odysseus a great deal of helpful information. He explains that "a god will make" the journey home very hard for him; Teiresias says that Poseidon is still very angry with Odysseus because Odysseus blinded his son, the Cyclops. He continues with additional information, saying that Odysseus must keep his men from eating the cattle that belong to the sun god, Helios, on the island of Thrinacia. If he can manage this, Teiresias says, "you all may still reach Ithaca . . . but harm them in any way, and I can see it now: / your ship destroyed, your men destroyed as well." If the men harm these cattle, then there is no possible way they will make it home. Further, Teiresias tells Odysseus what will happen to him when he gets home: he will find "arrogant men" eating up all his food and wooing his wife, Penelope. He will kill them all and then, eventually, after many years, his own death will be "gentle [and] painless." Odysseus will die as a very old man, surrounded by all the people that he loves.