"You're not responsible," she said, though her voice trembled. "It's the Professors - it's us who are responsible for student safety, not you."

Harry's eyes flicked back to her. "You're responsible?" There was a tightness in the voice. "You want me to hold you responsible, Professor McGonagall?"

She raised her chin and nodded. It would be better, by far, than Harry blaming himself.

The boy pushed himself up from where he was sitting on the floor, and took a step forward. "All right, then," Harry said in a monotone. "I tried to do the sensible thing, when I saw Hermione was missing and that none of the Professors knew. I asked for a seventh-year student to go with me on a broomstick and protect me while we looked for Hermione. I asked for help. I begged for help. And nobody helped me. Because you gave everyone an absolute order to stay in one place or they'd be expelled, no excuses. No matter what else Dumbledore gets wrong, he at least thinks of his students as people, not animals that have to be herded into a pen and kept from wandering out. You knew you weren't any good at military thinking, your first idea was to have us walking through the hallways, you knew some students there were better than you at strategy and tactics, and you still nailed us down in one room without any discretionary judgment. So when something you didn't foresee happened and it would've made perfect sense to send out a seventh-year student on a fast broom to look for Hermione Granger, the students knew you wouldn't understand or forgive. They weren't afraid of the troll, they were afraid of you. The discipline, the conformity, the cowardice that you instilled in them delayed me just long enough for Hermione to die. Not that I should've tried asking for help from normal people, of course, and I will change and be less stupid next time. But if I were dumb enough to allocate responsibility to someone who isn't me, that's what I'd say."

Tears were streaming down her cheeks.

"That's what I'd tell you if I thought you could be responsible for anything. But normal people don't choose on the basis of consequences, they just play roles. There's a picture in your head of a stern disciplinarian and you do whatever that picture would do, whether or not it makes any sense. A stern disciplinarian would order the students back to their rooms, even if there was a troll roaming the hallways. A stern disciplinarian would order students not to leave the Hall on pain of expulsion. And the little picture of Professor McGonagall that you have in your head can't learn from experience or change herself, so there isn't any point to this conversation. People like you aren't responsible for anything, people like me are, and when we fail there's no one else to blame."

The boy strode forward to stand directly before her. His hand darted beneath his robes, brought forth the golden sphere that was the Ministry-issued protective shell of his Time Turner. He spoke in a dead, level voice without any emphasis. "This could've saved Hermione, if I'd been able to use it. But you thought it was your role to shut me down and get in my way. Nobody has died in Hogwarts in fifty years, you said that when you locked it, do you remember? I should've asked again after Bellatrix Black got loose from Azkaban, or after Hermione got framed for attempted murder. But I forgot because I was stupid. Please unlock it now before any of my other friends die."

Unable to speak, she brought forth her wand and did so, releasing the time-keyed enchantment she'd laced into the shell's lock.

Harry Potter flipped open the golden shell, looked at the tiny glass hourglass within its circles, nodded, and then snapped the case shut. "Thank you. Now go away." The boy's voice cracked again. "I have to think."

— Harry Potter and the Methods of Rationality by Eliezer Yudkowsky