Orestes and Electra sneak into the throne room of the palace. They hear two soldiers approaching and hide behind the throne. The Soldiers talk about ghosts, discussing whether the ghost of Agamemnon would have enough weight to make the creaking sound they heard in the room. The conversation then turns to flies and how many of them seem to be around. Finally, one of the soldiers decides to check for the origin of the creaking sound. As the soldiers look behind the throne, Orestes and Electra sneak out, tiptoe around the soldiers, and then get back behind the throne. Seeing no one, the soldiers decide that it must be Agamemnon's ghost. Aegistheus enters with Clytemnestra and dismisses them.
Clytemnestra attempts to dissipate Aegistheus's bad mood, but Aegistheus says he is tired of ruling and maintaining the remorse of the entire city. He wishes he had not had to punish Electra because he can't bear the farce of his life any more. When Clytemnestra continues her attempts to comfort him, Aegistheus orders her to leave and then asks Jupiter whether he has been a proper king. Jupiter enters the throne room and addresses him. When Aegistheus does not recognize him, Jupiter calls down lightning to show who he is. He tells Aegistheus to summon his guards immediately and send them to arrest Electra and Orestes, but the king refuses, saying he is so tired that he would rather die. Jupiter reasons with him, saying that he has also had to play the same game of maintaining fear in people. He, too, is tired of it, and Aegistheus has nothing special to complain about. The king's murder of Agamemnon pleased the gods because it gave rise to a city of remorse. If Orestes were to kill Aegistheus, he would feel no remorse and this would be a waste, which is why Jupiter wants Orestes restrained.
When Aegistheus still refuses to take action, Jupiter reminds him that he became king out of a passion for order, which the god has given to kings. This order is maintained through fear and remorse, blinding people to their own freedom. Orestes, on the other hand, knows that he is free. Realizing that Orestes's freedom would shatter the order he has worked for, Aegistheus agrees to stop him.
As soon as Jupiter leaves and before Aegistheus has time to call his guards, Orestes and Electra appear from behind the throne and Electra orders her brother to strike. Aegistheus refuses to defend himself and Orestes hits him with the sword. Dying, Aegistheus grabs on to his killer and asks how Orestes can violate the law of the gods and not feel remorse. Orestes replies that he does not need god to tell him what is right. He then kills Aegistheus and goes on to Clytemnestra's chambers. Electra loses her nerve and tries to stop him. Orestes brushes her aside and goes on. While he kills the queen, Electra tries to convince herself that this is what she wants. When Orestes returns, she attempts to celebrate their victory, but the flies around them turn into The Furies, goddesses of remorse. Hearing guards approaching, Orestes decides to take sanctuary in the Shrine of Apollo for the night until he can speak with the Argives.
The farcical beginning of this scene indicates a turning point in the play. The soldiers' ridiculous conversation about fat ghosts and ghost flies along with the game of hide and seek around the throne introduce irreverent comedy into the grim plot. This brief interlude serves the essential dramatic function of lightening the tone in order to lower the audience's respect for the throne room and particularly the throne itself, on which much of the humor centers. Besides reducing our natural respect for the throne and what it stands for, power and order, the farce also undermines our natural dislike for murder. For Sartre's message to have its full effect, the audience must not be so disgusted by Orestes's action as to condemn his notion of freedom. Comedy is a natural way of breaking up the tension so that we may observe the murder scene with less distaste. Finally, the soldiers are speaking very seriously about ghosts and flies, but we see that their conversation is ridiculous. Though the Argives may believe in the dead coming back for a day, any attempt to analyze this idea only underscores its absurdity. Though elements of farce recur throughout the play, it is only here that they receive an extended scene. Structurally, this scene occurs directly in the middle of the play, informing us of an important break between previous events and upcoming ones.
The soldiers talk about the flies, noticing that there are many more than usual in the throne room. They attribute this to the day of the dead. In fact, the presence of the flies foreshadows what is about to take place. Orestes and Electra are about to commit murder, and the flies are there to ensure that the criminals are stung with remorse.