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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 sends for Tiresias, the blind prophet, and asks him
what he knows about the murder. 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. 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.