Third choral interlude.—Apropos of the fall of Troy, the chorus of Argive women sings the praises of Hercules whose arrows had been required by fate for the destruction of Troy.
Exode.—Clytemnestra returns and bids Cassandra, who still remains standing in her chariot, to join the other slaves in ministering at the altar. But Cassandra stands motionless, paying no heed to the words of the queen, who leaves the scene saying:
I will not bear the shame of uttering more.
Cassandra now descends from her chariot and bursts into wild and woeful lamentations. By her peculiar clairvoyant power she foresees and declares to the chorus the death of Agamemnon at the hands of Clytemnestra and Aegisthus, as well as the manner of it; she also foretells the vengeance which Orestes is destined to work upon the murderers. Her own fate is as clearly seen and announced, as she passes through the door into the palace.
Soon the chorus hears the death cry of Agamemnon, that he is "struck down with deadly stroke." They are faint-heartedly and with a multiplicity of counsel discussing what it is best to do when Clytemnestra, with blood-stained garments and followed by a guard of soldiers, enters to them from the palace. The corpses of Agamemnon and Cassandra are seen through the door within the palace. The queen confesses, describes, and exults in the murder of her husband. The chorus makes elaborate lamentation for Agamemnon, and prophesies that vengeance will light on Clytemnestra. But she scorns their threatening prophecies. In the end Aegisthus enters, avowing that he has plotted this murder and has at last avenged his father, Thyestes, upon the father of Agamemnon, Atreus, who had so foully wronged Thyestes. The chorus curses him and reminds him that Orestes still lives and will surely avenge his father.
Exode.—Cassandra, either standing where she can see within the palace, or else by clairvoyant power, reports the murder of Agamemnon, which is being done within.
Electra urges Orestes to flee before his mother and Aegisthus shall murder him also. Very opportunely, Strophius comes in his chariot, just returning as victor from the Olympic games. Electra intrusts her brother to his care, and betakes her own self to the altar for protection.
Electra, after defying and denouncing her mother and Aegisthus, is dragged away to prison and torture, and Cassandra is led out to her death.