Disclaimer: I do not own Harry Potter.
Author's Note: I found it interesting that Cedric's death in the movie was quite different from in the book. In the book he just died, without saying anything, but in the movie, he tried to defend Harry and go out like a hero. This is my attempt at Harry's reaction after the movie scene.
Crushed By Guilt
"Who are you and what do you want?"
The words haunt Harry as he lies, weeping, on top of Cedric Diggory's body, refusing to let him go. Those words were the last words Cedric ever spoke, the last words to ever leave his mouth before Voldemort's soft voice told Wormtail to kill the spare. That's what he represented to them, nothing more than a spare who needed to be eliminated, and it causes Harry to feel despair well up from the bottom of his stomach.
All his life, despite his abominable treatment by the Dursleys, he's tried to do the right thing, tried to help people. Nobility is a quality he truly admires, and all he was trying to do was to be there for Cedric, to reach out a hand to him and let him share the victory. Earlier in the year, he resented Cedric, for getting the girl he fancied, and looking like a true champion. But he knew, deep in his heart, that this was a dumb reason to dislike somebody, so at the end, when all was said and done, and they both reached the cup at the same time, he wanted to show the older boy that he could reach out, he could make Hogwarts proud with Cedric at his side. The truth was, he didn't want to be in the tournament in the first place, and the look on Cedric's face showed that he desperately yearned to do something to honor the magnificent castle.
But look where Harry's selflessness got Cedric. Dead, without a second thought from Voldemort or Wormtail. They just let him lie there, his gray eyes emptily staring, staring, staring up at the night sky, that final look on his face one of terror but defiance. He had tried to defend Harry, tried to go out like a hero. It makes Harry sob with misery and guilt. Why hadn't he been able to do anything to save Cedric? All he was able to do was to watch him collapse next to him, his face frozen in that look of determination and shock. How is he supposed to tell the school what happened? How is he supposed to face Cho every single day now, knowing he's the reason her boyfriend is dead?
When Mr. Diggory starts yelling in heart-wrenching agony, it only makes Harry cry harder. He took Cedric away from a loving father who was totally devoted to him. His son, his only son, his cherished, strapping young son, is dead all because Harry tried to be bloody noble. It's so unfair. Moments earlier, all he had been able to choke out to Dumbledore was, "He's back! He's back! Voldemort's back! Cedric, he asked me to bring his body back! I couldn't leave him, not there!" Oh, God, why did Cedric try to defend him? He didn't deserve it, he had brought the boy to his death in the first place!
Are you happy now, Ron? He thinks bitterly as Mr. Diggory's cries sound like a wild animal in pain. You swore I liked my fame, is this what you want? To be laying on top of a body, weeping with guilt and heartbreak? Do you really want to see somebody die, to see the life leave their eyes as if it had never been there in the first place? Do you really want to feel inadequate, as though you are nothing, and you're too slow to save a person who had their whole life ahead of them? More crushing guilt sweeps over Harry as he remembers how much he had resented Cedric, and how all that seems irrelevant now.
As he is carried back into the school by Mad-Eye Moody, he knows he will never, ever forget this night. He will forever be haunted by Cedric's empty, lifeless gray eyes. In his nightmares, those eyes will look at him accusingly, demanding to know why the light had to leave them. Why did you murder me, Harry, when I was nothing but nice and sportsmanlike to you? They will ask through their emptiness. And Harry will never have an answer. As he sits in the office and tries to calm down from his tears, he knows his innocence has forever been lost. He will hate and blame himself for this for a long, long time, for he knows in his heart that he was the one who murdered Cedric. It is entirely his, Harry James Potter's, fault, and no empty words will ever be able to convince him that it isn't true. I'm so sorry, Cedric, he thinks miserably as one last tear trickles down his cheek.