Clytemnestra returns and brusquely orders Cassandra to enter the palace and stand with the other slaves near the altar, since Zeus has ordained her slavery. She should not be proud. Even Heracles was sold as a slave once, and Cassandra should at least be grateful that she has come to a family with old money; nouveaux riches are cruel to their slaves, but here she will be treated appropriately. The Chorus Leader urges Cassandra to obey. If she doesn't speak some barbarian language, Clytemnestra says, she should be able to understand me. Growing impatient, she calls Cassandra crazy and goes in. The Chorus Leader pities her and urges her to "submit to the unaccustomed yoke" (1071).
Finally Cassandra speaks, uttering a cry of lamentation and calling on Apollo in her despair. The Chorus Leader is surprised that she would call on Apollo in such terms-he has nothing to do with lamentation. Then the Leader realized she is going to prophesy, that her gift of prophecy has not left her. She continues to call on Apollo as her destroyer, asking him where he has brought her. The Leader tells her she has come to the house of Atreus's sons, but she says that it is "a house that hates the gods, one that knows many sad tales of kindred murder" (1090-1091). She speaks of children slain; indeed in her prophetic trance she sees the children weeping at the door of the palace, and she speaks of a father eating their flesh; the Leader recognizes the horrible old story, but when she speaks of a new evil coming, the Leader cannot understand her, though she speaks more and more clearly, seeing in her prophetic frenzy a wife giving her husband his ritual bath, then stretching out her hand to murder him. She sees the net that will entangle him, and bids the Furies shout over the murder. The Chorus Leader feels fear and foreboding, but distrusts her words.
Then Cassandra sees her own death coming, and mourns for herself and for the destruction of her city. Then she seems to come out of her trance, and says that now she will speak clearly. A choir of Furies has haunted this house, singing of the deed that began the trouble, when a brother slept with a brother's wife. Swear, she tells the Chorus, that you know I am speaking the truth. The Leader acknowledges it and marvels, since she comes from so far away. She explains that Apollo gave her the gift of prophecy and she promised to sleep with him. When she did not keep that promise, he ordained that she would never be believed. But we believe you, says the Leader.
Cassandra calls out in pain, as she is once more taken over by the prophetic trance. Again she sees the slain children, this time holding in their hands their own flesh, and declares that "a cowardly lion" (1224) is plotting revenge for this slaying, one who has been sleeping in the master's bed and awaiting his return. The master, the commander of the Greeks, does not know that the evil woman who smiles and pretends to rejoice at his homecoming is plotting to kill him, a monstrous killing, the killing of the male by the female. If you don't believe me, she says, it will still happen, and then you will pity me.
Indeed the Chorus can only understand and believe the old story of how Thyestes unknowingly ate his children's flesh. Cassandra speaks yet more clearly, telling them they will see Agamemnon's death, and their reaction is to tell her to be quiet, then to ask what man will do the deed. She is taken over by trance again, and sees her own fate: "This two-footed lioness that beds / with the wolf in the noble lion's absence / will kill me, poor wretch" (1258-1260) and boast that she is killing him to pay for his bringing me back. Cassandra tears off and throws away the symbols of her status as a prophet, seeing that it is really Apollo, who has brought her to this fate, now taking away the "gift" he gave. She must die, yet the gods will send an avenger who will slay his mother and atone for his father. Having seen Troy vanquished and Troy's conquerors suffering, why should she lament her fate? She prays for an effective stroke that she may die without a struggle.
The Chorus Leader asks why, if she knows what is coming, she goes without fear to her death. She answers that she knows there is no escape, no point in running. The Leader praises her courage and speaks of the happiness of a glorious death, but she feels only the sadness of the fate of her father and his children. She moves toward the door of the palace, then recoils in horror at the smell of murder. As a last farewell, she asks that when vengeance is taken, it may be for her as well as for Agamemnon, then lamenting the pity of human life, fragile as it is, she goes into the palace.
The Chorus chants: If this man, so fortunate, able to take Troy, is now about to die as a penalty for other deaths, what human being can be so fortunate as to be beyond the reach of disaster?
In ancient Greece, it was thought to be a part of prophecy to know the past and present as well as the future. Thus through Cassandra, Aeschylus can remind the audience of the horrible past of the house of Atreus, and the part it played in bringing about Agamemnon's destruction, and he can do it with great power, as Cassandra in her prophetic trance seems to see the old horror. The story is briefly this: Atreus was king, and his brother Thyestes seduced Atreus's wife. Some versions of the story add all sorts of complexities, but Aeschylus sticks to the basics: Atreus, feeling his power threatened, sent Thyestes into exile. Then when Thyestes returned as a suppliant, Atreus pretended to forgive him, but took vengeance on him by killing his sons, feeding Thyestes their flesh at a banquet, and then telling the father what he had eaten. Horrified, Thyestes went into exile, taking his remaining son, Aegisthus, with him. Aegisthus, seeking revenge on Atreus's son, came to Argos while Agamemnon was besieging Troy and became Clytemnestra's lover. Cassandra never names him, but he is the "cowardly lion" she speaks of, the wolf who has bedded the lioness. Cassandra does not tell the whole story-when Aegisthus finally comes on stage, he does that-she rather sees the horror of the slain children, and the vengeance that will be visited on Agamemnon for his father's sins.
Bringing in the old horror in this way, Aeschylus opens up the possibility of the audience having some sympathy for Agamemnon, trapped by the curse that Thyestes called down on the whole family. At the same time, our sympathy for Clytemnestra is lessened: For one thing, Clytemnestra speaks harshly to Cassandra, and Cassandra tells us that she too, despite her complete innocence, will die at Clytemnestra's hands. For another, Cassandra's horror at the idea of the female killing the male carries weight, since it is a woman who expresses it.
Accordingly, when Cassandra speaks of the avenger (Orestes, son of Agamemnon and Clytemnestra) who will come and slay his mother, and thus avenge not only Agamemnon but her wretched self, the audience-at least an ancient Greek audience-might be expected to have some sympathy for that avenger, horrible as is the thought that a man could kill his mother. The courage with which Cassandra goes to her death gives this part of the play a strong tragic quality, tragic in the sense that we admire this heroine even as we pity her.