Aeschylus 
Libation Bearers 

In Libation Bearers, the second play of Aeschylus' Oresteia trilogy, many years after the murder of Agamemnon, his son Orestes returns to Argos to exact vengeance on his mother Clytaemnestra for killing the king. Upon arriving, Orestes reunites with his sister Electra at Agamemnon's grave, while she was there bringing libations to Agamemnon in an attempt to stop Clytemnestra's bad dreams. Shortly after the reunion, both Orestes and Electra, influenced by the Chorus, come up with a plan to kill both Clytemnestra and Aegisthus. But revenge, instead of bringing inner peace to Orestes, will become his condemnation.