As Sophocles' "Oedipus Rex" begins, the people of Thebes are begging the king for help, begging him to discover the cause of the plague. Oedipus stands before them and swears to find the root of their suffering and to end it. Just then, Creon returns to Thebes from a visit to the oracle. Apollo has made it known that Thebes is harbouring a terrible abomination and that the plague will only be lifted when the true murderer of old King Laius is discovered and punished for his crime. Oedipus swears to do this, not realizing that he is himself the culprit. The stark truth emerges slowly over the course of the play, as Oedipus clashes with the blind seer Tiresias, who senses the truth. Oedipus remains in strict denial, though, becoming convinced that Tiresias is somehow plotting with Creon to usurp the throne.