Oedipus Tyrannus is considered Sophocles's masterpiece and is probably the most famous of all the Greek tragedies. Aristotle deemed it a perfect play. First performed about 425 b.c., not long after a plague had ravaged Athens, Oedipus Tyrannus is set in Thebes, a city falling to ruin from a similar calamity. King Oedipus is told that the city will continue to suffer until the murderer of the previous king is brought to justice. Oedipus vows to discover the evildoer's identity and to punish him. Unaware that he himself is the killer, Oedipus relentlessly pursues the truth until he discovers his own guilt and blinds himself so that he may never see his father in the afterworld.