The document provides a summary of the Greek tragedy Oresteia by Aeschylus. It describes how Queen Clytemnestra murders her husband King Agamemnon and his mistress Cassandra in revenge for his sacrifice of their daughter Iphigenia. This displeases Apollo, who instructs Agamemnon's son Orestes to avenge his father's death by killing his mother Clytemnestra with the help of his sister Electra. The summary includes details about the author, number of pages, publisher and year of publication for an edition of the play.