Sixty seconds.
Harry took a deep, shuddering breath. Let it out. Calm born of desperation managed to gift him with some semblance of the icy calm of his Dark Side.
Lord Voldemort was going to kill him.
Harry didn't want to die.
He had a wand he couldn't even raise without being killed. He was naked save for his glasses. Surrounded by thirty-six Death Eaters and Voldemort.
He didn't have any instant escape options. His mind flashed to Fawkes and how the Phoenix had rejected him after his use of the Killing Curse.
Fighting his way out was so astronomically improbable that it was best to forgo the option completely. No playing the action hero.
Among the little skills he had in magic that Voldemort didn't have was incomplete transfiguration, which was silent. Perhaps an instant cylinder of air under his feet, dropping him in, which would then close up.
His mind flashed back to the eraser, and the exhaustion that came with it.
No, it cost to much effort to do anything effective. Any attempt would leave him dead on his feet and in a hole of air that would kill him once it reverted. Not that he honestly believed he could transform that much within a few seconds.
No to the science hero, also.
He could only talk in Parseltongue, which meant the only person he could convince to help him was Voldemort. Yeah, right.
Among the three options, two led to instant death at the hands of the Death Eaters.
Guile hero it was then.
Thirty seconds.
Lord Voldemort was going to kill him.
Harry didn't want to die.
He had his mind. He didn't want to die. To defeat Voldemort, he would need time. He would need to live. What was the best way to use what he had to get the other?
What did he know about Voldemort? No. The one standing across from him admitted to him that even Voldemort was just a mask.
They were speaking Parseltongue. Only the two of them could understand each other. What did he know about Tom Riddle?
Ten seconds.
Tom wanted to survive.
Tom wanted the world to live.
Tom wanted power.
Tom was studying rationality thanks to Harry - don't think about that - but wasn't a master.
Five seconds.
Tom was a wizard.
Tom would expect kindness in plots now.
Tom didn't want to be redeemed.
Tom couldn't use magic on Harry directly.
Tom would do anything to live.
Tom - STOP THAT'S IT!
"You shouldn't kill me, and you shouldn't maim me," Harry began in Parseltongue. "It is not in your best interest to do so."
"Ah," Volde- Tom raised an eyebrow that didn't exist. The voice, even in Parseltongue, was high, cold, mocking. "So explain how it is in my best interest to let you live, in detail, and why you wouldn't try to work against me."
Harry trembled, then stilled. Make it seem like he has the upper hand, he thought frantically. "I could swear another oath. I could submit. I do remember your lessons. I could lose with grace."
Not a single lie, but nothing promised. Sweat broke out on his forehead, his wand arm twitched. His nose twitched and he consciously reminded himself that to scratch it would cost his life.
"I taught you to pretend to lose," Tom corrected coldly, "And I have yet to hear a reason as to why you are more useful to me alive than dead, especially when the prophecy states you could destroy the world."
Harry grasped at that, jerking his body minutely as though shocked, "But I wouldn't!" He hissed, "How am I even supposed to know what you think I will do if I don't know the prophecy?"
"You don't," Tom hissed back, "And that is the point. Do not think to ask for the prophecy either, boy. I will not give it to you."
"But what if the prophecy is already in motion," Harry insisted, "what if I have already provided all that is needed for it to happen? You saw my influence on those in Hogwarts. Already, Draco Malfoy is not the racist Pureblood he was before. So many have already listened to what I've told them. What if my influence was to inspire another to commit what you feared would happen?"
Tom twitched. Smiled that snake grin.
"So I will monitor those students," He hissed, "And if any come close to the kind of power that could destroy the world, I will prevent them."
The unspoken message caused a shiver to run through Harry, and he hoped that he hadn't inadvertently killed the entire student population.
"All of them," Harry asked, "and do you really think that none will slip through the cracks? Do you really think a prophecy is so easily avoided?"
Tom's eyes narrowed and flashed.
"...I think you are stalling," Tom's anger was palpable, and the air hummed. "At the beginning of the conversation, you made the statement that it was in my best interest to spare you, and that you wouldn't deliberately attempt to destroy the world. Everything else you said was either conditional, a question, or hypothetical. Answer honestly right now, or I will kill you, in either yes or no. Do you have some form of magic or knowledge that I do not have?"
"Yes."
"Are there any beyond your skills I've already mentioned, your muggle knowledge, and your partial transfiguration skill that you used in Azkaban?"
"No."
Tom glared at the boy. "Now, why did you say it was in my best interest to not kill you? Explain your reasoning. Directly, or I shall kill you immediately."
Harry swallowed harshly.
"I was stalling. But it isn't in your best interest to kill me. Despite what you say, your soul is still inside me. I am your horcrux, and to kill me would remove an instrument of your immortality. You desire to live, I am unlikely to ever succeed at killing you, therefore it would be in your best interest to not kill me. There have been cases of pain and blood loss causing death, so it wouldn't be in you best interest to maim me either."
Harry took a deep breath. He was sweating my the gallon now. His hand was shaking visibly, and he was having trouble staying on his feet.
He would only have the one shot. He'd have to make it count.
He'd managed to continue the conversation by nearly three minutes.
In those three minutes he'd managed to slowly transfigure a lot of air from the stone underneath them. Wand facing down, naturally.
In those three minutes, the heavily breathing mass of Death Eaters had managed to use up a lot of oxygen in the cramped room.
Over on the altar, the jewel on his ring exploded as it reverted to the enormous rock. The moment came.
In every living being, there is an instinctual response towards loud concussive sounds, especially in moments of high tension. That is, to turn and look for it. In that one moment that Harry had, he released the magic in the room that kept all the transfigured oxygen stable with a deft, albeit shaking twist of the wrist.
Suddenly, a lot of the oxygen in the Death Eaters' bloodstreams were not. They remained standing, and Harry moved. He doubted that Tom didn't have a bubblehead charm already on him. Too smart to not have one. Harry himself had one as an enchantment on his glasses that he had gotten one of the older students to do for him for a war game.
However, Voldemort had admitted himself that the Death Eaters were wearing nothing but transfigured objects to act as masks and robes. And the enchantments on the originals had long since worn out. And while Harry might have expected Tom to bluff him over that like he did moments prior, he doubted that the Death Eaters were operating on the same level.
Thirty-six Death Eaters dropped dead instantly as the oxygen in their brains turned to calcium, most likely causing massive hemorrhages. Voldemort had already raised his own gun towards Harry, but Harry had taken the moment of distraction to target the gun as well.
The transfiguration was nothing complicated, just enough to ruin and warp the important parts.
Tom screamed in frustration, going for his wand. Harry was already running towards his own bag on the altar.
Right before he managed to grab the bag, it was violently summoned from him. He didn't dare try to reclaim it.
The clothes he left, along with the rock.
He was running on adrenaline now. He hadn't felt this exhausted since Azkaban.
He was nearly to the door when a kick from behind knocked him over. Before he knew what was happening, he was dangling from the air, Voldemort's terrifying visage above him, and slowly suffocating as he was strangled.
"You-" Tom's grip tightened.
"You made a mistake Tom, minutes ago." Harry hissed out quickly. A moment of wounded pride caused the grip to slacken. Harry continued before he lost his chance.
"You imbued Hermione with Unicorn blood, and then you spilled it." The grip was loosening now. Harry continued frantically, trying to keep talking, trying to gain more time, "Quirrel's body may have been cursed, but your new one wasn't. You're cursed now, just as you were in the hospital wing, and no Unicorns in sight. Your followers are dead now-"
Harry dropped to the ground, the grip losing hold entirely. He collapsed. The stress and heavy use of transfiguration left him with nothing. He looked over to the body of Tom Riddle and recoiled.
The twisted face that looked so snakelike was melting. Whatever dark rituals used to sustain the Dark Lord's body and that of his previous host were absent, and the curse of spilled Unicorn's blood was catching up.
"It's not over," Tom muttered, pulling out the Philosopher's Stone. "It-"
"Accio." Harry muttered, the weakened spell barely managed to pull the stone from the Dark Lord's trembling fingers. Sent tumbling and skittering across the floor.
Harry expected some sort of parting curse, or some other climatic one-liner that most villains gave at the end when bested.
Instead, with a quiet cough, the body fell away, reverting to a puddle of melted skin, blood, and bones.
He'll be back, Harry thought.
And didn't that make the victory bittersweet?
He looked over towards Hermione, and then over to the fallen Death Eaters.
Draco's going to murder me, Harry sighed.
And then he passed out.
A/N: This was originally made in response to the challenge on the last chapter of Harry Potter and the Methods of Rationality. I know that this isn't exactly following the spirit of the challenge that Yudkowsky issued. He wanted the readers to come up with some way for Harry to talk himself out of his situation with nearly no resources. In other words, to recreate the AI in the Box Challenge that he performed so long ago. I, however, am of the mind that while Harry's situation is technically hopeless, that Yudkowsky also left a lot of minor Chekhov's Guns lying around. The stone, the partial transfiguration skill, the numerous hints from instructors that making a gas was dangerous, and the number of skills that Harry picked up from the war games. Also, there were the Death Eater's own lack of genre savvy and Voldemort giving Hermione unicorn blood and then cutting her, thereby cursing himself, which would have greater effect since his own new body lacks all the dark ritual boosts his others would have (also the fact that he never drank any blood in this body, which I guess would go a long way to mitigating these effects). And don't forget Harry's transfiguration, which is silent.
Needless to say that there were a lot of random bits of plot devices lying around, and I decided to have Harry use as much of them as he could, all the while technically telling the truth. The fact that I ended the story with Voldemort's fate mirroring that in the first book is merely some ironic original flavor.
In the end, I went with Harry getting some luck, Voldemort falling to his own vice of pride, and the end result of what happens when giving the characters some seriously broken powers. I suppose that everyone was just Too Clever For Their Own Good.