The citizens of Thebes beg their king, Oedipus, to end the plague threatening the city. The oracle instructs that finding the murderer of the former king, Laius, will end the plague. Oedipus sets out to solve the murder. The prophet Tiresias accuses Oedipus of killing Laius, which Oedipus rejects. However, Oedipus realizes he fulfilled a prophecy by killing a man at a crossroads, like Laius. It is discovered that Oedipus unwittingly killed his own father and married his mother, realizing the prophecy has come true.