Clytaemestra exultingly says that now she can reveal herself and speak the truth. She tells how she trapped Agamemnon in a net as he stepped from his bath and hacked him to death with three blows of an axe. She laughed with joy as the blood from his wounds splattered her.
The elders are stunned by Clytaemestra's sadistic arrogance. She mocks them for having thought she was an ordinary, weak woman and cries defiantly:
You can praise or blame me as you will;
it is all one to me. That man is Agamemnon,
my husband; he is dead; the work of this right hand
that struck in strength of righteousness. And that is that.
The elders threaten that Clytaemestra will be banished from Argos for these murders, but she retorts that Agamemnon was not banished for the murder of Iphigenia and demands to know how they can speak of justice when they were willing to tolerate that heinous crime. Clytaemestra insists that the murder of Agamemnon was justified — partly because of the sacrifice of Iphigenia and his infidelity with Cassandra and other women while at Troy, but also because she has acted as an agent of the gods and helped to fulfill the curse on the House of Atreus.
The elders continue to lament for the dead Agamemnon and to argue with his murderer. Finally Clytaemestra manages to calm them. They still condemn her crime, but a basis for understanding has been reached because they are unable to deny her conviction that the murder was righteous. They are also reassured by her insistence that she has no intention of taking advantage of the people of Argos now that their king is dead.
At this moment, Aegisthus enters, followed by a troop of soldiers. He is happy about the death of his old enemy and gives a brief account of his grievances against Agamemnon as an additional justification for the murder.
The elders resent Aegisthus' gloating and accuse him of cowardice and effeminacy. Some heated insults are exchanged and swords are drawn. The elders, though old men, are about to engage in a fight with the soldiers of Aegisthus when Clytaemestra asserts her authority and takes control of the situation. She says there has already been enough violence and bloodshed, and urges both factions to put down their weapons.
The elders continue to defy Aegisthus, for they realize that Clytaemestra intends to share the throne with him. They warn that the citizens of Argos will rise up against him and that Orestes will return to avenge his father's murder.
Aegisthus angrily threatens to punish the elders for their insolence, but Clytaemestra advises him to ignore the impotent rantings of weak old men. After all, she says, the power in Argos is now in their hands, and they will rule severely. The chorus files out and the play ends.
Clytaemestra is no longer obligated to restrain herself or conceal her inner thoughts in this final scene. She exults openly after killing her husband and shows no remorse or shame. She proudly asserts that her acts were righteous, and the elders are unable to contradict her because so many ethical strands have become tangled by the tragic history of the family of Atreus. Clytaemestra also defies the threats of the chorus and asserts her control over Aegisthus and the kingdom. It can now be seen what bitterness had built up within her while Agamemnon was still alive, but she demonstrates superb poise and self-possession at the height of her triumph. The central place that Clytaemestra has held in the tragedy is emphasized by the fact that she speaks the last lines of the play, for normally this privilege was reserved for the chorus.
Agamemnon ends on a note of hostility and tension. Nothing has been resolved by the murder, for even the resolute Clytaemestra has a faint realization that the curse is as potent as ever and that she will have to pay for her crime. Agamemnon is about murder and revenge, but the tragedy also has serious philosophical undercurrents concerning the nature of justice and the relations of humans with god and between themselves.