In Aeschylus’ The Libation Bearers , the second play of his Oresteia trilogy , the story continues the cycle of vengeance that began with the murder of Agamemnon. The play opens with Orestes, the son of Agamemnon and Clytemnestra, returning to Argos to avenge his father’s death. Commanded by Apollo, Orestes and his sister Electra plot to kill Agamemnon’s murderers—their mother Clytemnestra and her lover Aegisthus.