As the play opens, Oedipus, king of Thebes, receives a group of citizens led by an old priest. The priest describes the plague that is destroying the city — a blight on the land causing famine and sickness. Recalling Oedipus' early triumph over the Sphinx, the priest begs the king to save Thebes once more.
Oedipus expresses his sympathy and concern, and announces that he has already sent his brother-in-law Creon to the oracle in an effort to end the plague. As Oedipus speaks, Creon returns with the oracle's message: The plague will end when the murderer of Laius (the former King) is killed or banished.
Oedipus immediately swears to take action to find the murderer and save the city.
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