Harry Potter and the Methods of Rationality

The alarm in Harry Potter's voice was contagious. Without even thinking about it, Draco's hand went into his robes and clutched at his wand. He'd thought the House of Malfoy was safe, so long as you only married into families that could trace their bloodlines back four generations you were supposed to be safe, it had never occurred to him before that there might be nothing anyone could do to stop the end of magic. "Harry, what do we do?" Draco's voice was rising in panic. "What do we do?"

"Let me think!"

After a few moments, Harry grabbed from a nearby desk the same quill and roll of parchment he'd used to write his pretend paper, and started scribbling something.

"We'll figure it out," Harry said, his voice tight, "if magic is fading out of the world we'll figure out how fast it's fading and how much time we have left to do something, and then we'll figure out why it's fading, and then we'll do something about it. Draco, have wizarding powers been declining at a steady rate, or have there been sudden drops?"

"I... I don't know..."

"You told me that no one had matched the four founders of Hogwarts. So it's been going on for at least eight centuries, then? You can't remember hearing anything about the problems suddenly appearing five centuries ago or anything like that?"

Draco was trying frantically to think. "I always heard that nobody was as good as Merlin and then after that nobody was as good as the Founders of Hogwarts."

"All right," Harry said. He was still scribbling. "Because three centuries ago is when Muggles started to not believe in magic, which I thought might have something to do with it. And about a century and a half ago was when Muggles began using a kind of technology that stops working around magic and I was wondering if it might also go the other way around."

Draco exploded out of his chair, so angry he could hardly even speak. "It's the Muggles -"

"Damn it!" roared Harry. "Weren't you even listening to yourself? It's been going on for eight centuries at least and the Muggles weren't doing anything interesting then! We have to figure out the real truth! The Muggles might have something to do with this but if they don't and you go blaming everything on them and that stops us from figuring out what's really going on then one day you're going to wake up in the morning and find out that your wand is just a stick of wood!"

Draco's breath stopped in his throat. His father often said our wands will break in our hands in his speeches but Draco had never really thought before about what that meant, it wasn't going to happen to him after all. And now suddenly it seemed very real. Just a stick of wood. Draco could imagine just what it would be like to take out his wand and try to cast a spell and find that nothing was happening...

That could happen to everyone.

There would be no more wizards, no more magic, ever. Just Muggles who had a few legends about what their ancestors had been able to do. Some of the Muggles would be called Malfoy, and that would be all that was left of the name.

For the first time in his life, Draco realized why there were Death Eaters.

He'd always taken for granted that becoming a Death Eater was something you did when you grew up. Now Draco understood, he knew why Father and Father's friends had sworn to give their lives to prevent the nightmare from coming to pass, there were things you couldn't just stand by and watch happen. But what if it was going to happen anyway, what if all the sacrifices, all the friends they'd lost to Dumbledore, the family they'd lost, what if it had all been for nothing...

"Magic can't be fading away," Draco said. His voice was breaking. "It wouldn't be fair."

Harry stopped scribbling and looked up. His face had an angry expression. "Your father never told you that life isn't fair?"

Father had said that every single time Draco used the word. "But, but, it's too awful to believe that -"