A plague has stricken Thebes. The citizens gather outside the palace of their king, Oedipus, asking him to take action. Oedipus replies that he already sent his brother-in-law, Creon, to the oracle at Delphi to learn how to help the city. Creon returns with a message from the oracle: the plague will end when the murderer of Laius, former king of Thebes, is caught and expelled; the murderer is within the city. Oedipus questions Creon about the murder of Laius, who was killed by thieves on his way to consult an oracle. Only one of his fellow travelers escaped alive. Oedipus promises to solve the mystery of Laius’s death, vowing to curse and drive out the murderer.
Oedipus sends for Tiresias, the blind prophet, and asks him what he knows about the murder. Tiresias responds cryptically, lamenting his ability to see the truth when the truth brings nothing but pain. At first he refuses to tell Oedipus what he knows. Oedipus curses and insults the old man, going so far as to accuse him of the murder. These taunts provoke Tiresias into revealing that Oedipus himself is the murderer. Oedipus naturally refuses to believe Tiresias’s accusation. He accuses Creon and Tiresias of conspiring against his life, and charges Tiresias with insanity. He asks why Tiresias did nothing when Thebes suffered under a plague once before. At that time, a Sphinx held the city captive and refused to leave until someone answered her riddle. Oedipus brags that he alone was able to solve the puzzle. Tiresias defends his skills as a prophet, noting that Oedipus’s parents found him trustworthy. At this mention of his parents, Oedipus, who grew up in the distant city of Corinth, asks how Tiresias knew his parents. But Tiresias answers enigmatically. Then, before leaving the stage, Tiresias puts forth one last riddle, saying that the murderer of Laius will turn out to be both father and brother to his own children, and the son of his own wife.
After Tiresias leaves, Oedipus