Agamemnon Must Die

The royal family of Mycenae has a bloody, monstrous history. Agamemnon returns with his war trophy, the Trojan Princess Cassandra whom he unthinkingly flaunts before his queen. After an epic sword fight in his own banquet hall, Agamemnon is killed. Cassandra has her nightmares/visions of the gory and unspeakable deeds of the House of Atreus; she is led away to be executed. Clytemnestra and her lover Aegisthus have their respective reasons, but this regicide must be avenged. Or so say the voices in Orestes' head. He must avenge his father. He must kill the regicides. He must kill his own mother.

But killing one's own mother would break the greatest of ancient taboos and would result in even more voices in his head. Are they just voices? Can they be placated?