In book 10, Odysseus learns from Circe that he and his men must visit the Underworld to receive important information from Tiresias, the blind prophet. Although Circe leaves careful instructions, Odysseus's men, not surprisingly, are unhappy to have to visit the land of the dead.
There, Odysseus does meet Tiresias, along with many other famous dead people. Tiresias tells him that Poseidon is punishing the Achaeans because of Polyphemus's blinding. More importantly, after foretelling events that will happen, Tiresias warns Odysseus not to touch the flocks of the sun in Thrinacia—unless he wants more trouble, including losing his crew.
Also notable is Odysseus's meeting with his dead mother, Anticleia, who he had not known had died. She tells him it was grief over him that killed her. Odysseus as well sees Tantalus, a man who is punished by being shown grapes and water, only to have them fade or pull away whenever he tries to eat or drink them. Spooked by all the dead clamoring around him, Odysseus finally flees Hades.