Summary of Aeschylus's The Libation Bearers

Greek Mosaic depicting a Libation

Agamemnon has been murdered by his own wife, Clytemnestra as soon as he returned from the Trojan War. Many feel this act is unjust, and strongly wish for Justice to be enforced, especially Agamemnon's son, Orestes. Orestes has been placed in exile by Clytemnestra for quite sometime, she claims that this was done for his own protection. Orestes, having heard about his father's murder, rushes to Agamemnon's corpse incognito to mourn. As he bitterly mourns, his sister, Electra, followed by the Chorus of enslaved Trojan women, see Orestes in disbelief. Evidently the two hadn't seen each other since they were quite young; proper identification is difficult followed by a joyous reunion. Electra discusses the nature of their father's murder and begin to plot vengeance.
Orestes plots to disguise himself as a traveler to penetrate the heavily guarded palace walls. Then as soon as he enters he kills both Aegisthus (Clytemnestra's lover) and Clytemnestra. The Chorus and the olympian Apollo support his plan, easily creating sympathy toward the two orphaned children. His plan changes, however, when Clytemnestra unexpectedly answers to disguised Orestes' knocking. To further conceal his identity, Orestes pretends to be a messenger announcing Orestes' death. Clytemnestra mourns and sends Orestes' old nurse for Aegisthus and his bodyguard to hear of the news. The Chorus convinces the nurse to just send Aegisthus alone, and so he does. Aegisthus meets Orestes off stage and is killed, his death is announced by a messenger to the audience.
Chaos breaks out in the palace, and Clytemnestra sense something is wrong, she finds Orestes by Aegisthus' corpse. It was her turn to receive Justice. Cunning Clytemnestra puts herself at Orestes' knees, begging him to remember their familial connection. He is nearly convinced to spare her life, but when one of Orestes' friends, Pylades arrives, he reminds Orestes of Apollo's will. He stabs his mother to death, in an act of Justice.
The Furies are enraged, seeing Clytemnestra's murder as an act of injustice.