The basic plot is as follows: Agamemnon is killed by Clytemnestra and
her lover Aegisthus after he returns from the Trojan war to reclaim his
sister-in-law Helen from the Trojans. Electra and her brother Orestes
plot to kill their mother and her lover to revenge his death. Both
authors wrote about the same plot, but the built the story very
differently. Sophocles focused on Orestes, and Euripides focused more
on the life of Electra.
In Sophocles's version, the play opens with Orestes learning his fate
from the Pythian Oracle; he must revenge his father's death unarmed and
alone. He sends his pedagogue Pylades, as a spy, to learn about the
situation in Mycenae. Electra mourns for her father's death. She is
unable to avenge her father's murders without the help of Orestes, her
brother. She is also mad about how her mother and her lover waste her
father's riches and desecrate his name. Her half-sister Chrysothemis is
no help to Electra and refuses to help in the murder of her mother and
mother's lover. Pylades arrives bearing the sad news of Orestes death.
He tells Clytemnestra that Orestes was killed in a chariot race at the
Delphian games; his body was cremated and his ashes were sent to
Mycenae. Concealing his identity, Orestes arrives and with the help of
Electra and Pylades, plots the murder of his mother and his mother's
lover. Orestes enter the palace, kills his mother and returns to
Electra. When Aegisthus arrives, Orestes kills him as well fulfilling
his destiny.
Euripides's version is much more dramatic. The play begins with
Electra's marriage to a peasant. Aegisthus had tried to kill Electra
but Clytemnestra convinced him to allow her to live. He decided to
marry her to a peasant so her children will be humbly born and pose no
threat to his throne. Orestes and Pylades arrive. Orestes says that he
has come to Apollo's shrine to pledge himself