The Riddle of the Sphinx
The lion-bodied Sphinx guarded Thebes, killing all who failed her riddle: "What goes on four legs in the morning, two at noon, and three in the evening?" Oedipus answered, "Man." The monster killed itself in shame, he was made king and married the newly widowed queen — not knowing the old man he had killed on the road was the king, and the queen before him his own mother.
Hunting the Killer to Himself
Years later plague ravaged Thebes, and the oracle demanded the killer of the old king be found. Oedipus swore to see it through, and as the testimony peeled back layer by layer, the killer was himself and the wife his mother. The queen hanged herself; he blinded himself with her brooch-pin and exiled himself. He made not one wrong move in the whole play — which is the deepest horror of all.