Even before you read Oedipus, you’ve already consumed the story, processed its inherent ickiness and general unlikeliness, which makes it difficult to come at the text fresh, with no preconceptions. You can’t even really experience the tragedy of it, because you know the outcome even as the first scene settles in. Oedipus may not know where he’s headed, but you and the rest of the audience sure do, and you end up reading the whole thing from between the fingers of your hand shielding your eyes from the proceedings.
Oedipus kills his father, marries his mother, and he proceeds to discover these facts for himself over the course of the horrifying play. Oedipus is a just ruler and a righteous man, and each step he takes toward the truth is inevitable for his character, which is what makes it so excruciating to watch as the whole thing unfolds.
The set up of the story is a bit rococo, which unfolds across several scenes, when we learn that Oedipus is only lately king of Thebes, having solved the riddle of the sphinx which had sat like a curse upon the land. I guess is was a pretty good way to become a king back then, to come along and help lift a curse on a city, and Oedipus earns his title as the just savior of the land. But the good times only lasted for a while because the city was beset by a new curse, which can only be lifted, turns out, when the killer of the former king is found.
The story was that the original kind had been on a journey and he was killed by a man he met on the road. Seems like a tough crime to solve after all these years. But then Oedipus reels out his back story a bit and we learn that when he was traveling on the way to Thebes he came upon a man at a crossroads and they fought over who would yield, and Oedipus ended up killing the man, which seems pretty harsh on Oedipus, frankly, but I guess life was tougher in old Greece. I suppose this is when the people in the original audience went, uh oh.
The stack of confounding circumstances thicken from there, with Jocasta, the late king’s widow and the current king’s wife, admitting that she had had a kid with the king whom they sent off to be murdered when it was prophesied that the kid would grow up to kill the king. And of course this story jogs the memory of Oedipus who mentions fled his own hometown when he was told that he was destined to kill his own father. Uh oh, indeed.
Like I said, it’s rococo. But it’s all in the service of the deadliest trap any character has found himself in since the invention of modern drama. Through his own diligence, honesty, and determination to be a good leader to his community, Oedipus doggedly uncovers the darkest of crimes and one of the worst stains that a man could bear, to kill his father and lay with his mother. It’s not just wrong, it’s icky.
The gravity of the offense is quickly reflected in the wife/mom, who promptly kills herself offstage, which is itself a kind of relief, like we get that she’s got to do that. Oedipus, on the other hand, responds more profoundly by poking his own eyes out, refusing to look again upon this world but remaining as a witness to his own abomination. I’m sure the audience would have been happier on their way out of the theatre if Oedipus had killed himself as well, but Sophocles knew justice was rarely so clean, and it was best to leave Oedipus in place to hector us, a reminder of how cruel the gods can be, rendering us helpless in the face of our own internal rot.
The inevitability of Oedipus’s discovery in the play makes it an exquisite torture for the viewer, even one who knows what is coming. But the power isn’t watching a character unwittingly pursue his own downfall. The power of the story is watching the realization that he was the problem all along, that his own destruction were written into him from birth, and he despite all his best intentions and fate-defying counter-maneuvers, he could never escape himself, never outrun the reality of who he actually was.