Why must odysseus go to the underworld (hades) after his stay in circe’s island, and whom does he meet while there?

purpose that he has to  the talk to the spirit of Tiresias, a blind prophet, who is supposed to be there and will be able to tell them how to get back home safely , Odysseus goes to rescue them, Hermes approaches him in the form of a young man. He tells Odysseus to eat an herb called moly to protect himself from Circe's drug and then lunge at her when she tries to strike him with her sword

answer; i believe that the correct answer is (north and south);

people are gonna need the passage.