In his tragedy, Euripides introduces startling and disturbing elements that ask his audience (and readers) to question the nature of tragic 'heroism,' assumptions of appropriate gender behavior, and the morality of both human characters and the gods.

Years before the start of the play, at the outset of the Trojan War, the Greek general Agamemnon sacrifices his daughter Iphigeneia in order to appease the goddess Artemis.

While his sacrifice allows the Greek army to sail for Troy, it leads to deep resentment from his wife, Clytemnestra, who also has born Agamemnon's other children, Orestes and Electra.

When Agamemnon returns victorious from the Trojan War ten years later, Clytemnestra (in some versions, helped by her lover Aegisthus) murder him in the bath.

Now grown, Orestes returns to Argos with Pylades, and he seeks out news of his sister Electra and considers how to revenge their father Agamemnon's murder.

Claiming to bring a message from her brother, Orestes keeps his identity hidden, even after he determines Electra's loyalty and her commitment to avenge Agamemnon's murder.

Mother and daughter alternate speeches of accusation, until Clytemnestra is invited into the cottage to help Electra with the birth ritual for her (fictional) newborn.

In the Odyssey, Orestes' return to Argos and taking revenge for his father's death is held up several times as a model for Telemachus' behavior (see Telemachy).