Odysseus is in the Underworld where he makes offerings in the way Circe has instructed. He sees many of the fallen; he sees Elpenor, and then he sees his mother; this is how he learns of her death.
While there he speaks to Teiresias, the blind prophet. Teiresias is only able to speak to him as a corpse because he's drinken the blood of the sacrifice. He goes onto tell him of things to come, and when they're done talking Odysseus asks if he can speak with his mother.
Antikleia must drink the blood of the sacrifice before speaking with him, but afterwards she tells him what is happening at home. Before Odysseus leaves he has a line of shades waiting to drink the blood of the sacrifice and speak with him........ guess there aren't many visitors down in the depths!