King Oedipus, mindful that a dreadful spell has fallen in Thebes, directs his brother-in-law, Creon, to pursue the advice of Apollo, the sun god. Creon tells Oedipus that the spell will vanish if the murderer of Laius, the previous king, is found and prosecuted. Laius was murdered several years ago at a crossroads.
Oedipus devotes himself to finding and prosecution of Laius’s murderer. Oedipus questions a variety of reluctant citizens, including a blind prophet named Teiresias. The blind prophet tells Oedipus that Oedipus was the murderer of Laius himself. This information really troubles Oedipus, but his wife Jocasta tells him to disregard what the prophet has said, “they’ve been wrong before.” As an example, she shares a story with Oedipus about how she and King Laius bore a son who was predicted to murder Laius and sleep with her. Jocasta and Laius had the child executed; therefore that prophecy didn't come true.
Jocasta's story doesn't ease Oedipus’ worries. When Oedipus was a child, an old man told him that he was adopted, and that he would ultimately murder his birth father and sleep with his birth mother. Not to mention, Oedipus previously assassinated a man at a crossroads, which very similar to the way Laius died. Jocasta commands Oedipus not to look into the past any more, but he stubbornly snubs her command. Oedipus goes on to interrogate a messenger and a shepherd, both of whom have knowledge about how Oedipus was deserted as a baby and adopted by a new family. In a moment of awareness, Jocasta comprehends that she is Oedipus’s mother and that Laius was his father. Disturbed at what has happened, she commits suicide. Shortly after, Oedipus also comprehends that he was Laius’ killer and that he’s been married to his mother; and has had children with her. In terror and misery, he gashes his eyes out and is expelled from Thebes.