The city of Thebes is going through a period of suffering and the people seek Oedipus for help. Oedipus learns that the solution to the problem is to banish the man who had killed the previous king, Laius, and Oedipus persists on finding the killer.
The blind prophet, Tiresias, is summoned to assist Oedipus. Instead, he attempts to persuade Oedipus not to seek the killer, but eventually exclaims that the killer is Oedipus himself. Tiresias then tells Oedipus of the prophecy that will be his fall. Oedipus sends Tiresias away and accuses Creon of treason.
After hearing that his [adoptive] mother had passed and learning more about his past, Oedipus gets the shepherd that was supposed to kill him when Oedipus was an infant. The shepherd persists on not telling the whole truth, but eventually, gives in after being pressured and tortured.