Very carefully, now... the bait is set, now the hook... "If you can learn to think of yourself as a human instead of a wizard then you can train and refine your powers as a human."
And if that instruction wasn't in every science curriculum, Draco didn't need to know it, did he?
Draco's eyes were now thoughtful. "You've... already done this?"
"To some extent," Harry allowed. "My training isn't complete. Not at eleven. But - my father also bought me tutors, you see." Sure, they'd been starving grad students, and it had only been because Harry slept on a 26-hour cycle, but leave all that aside for now...
Slowly, Draco nodded. "You think you can master both arts, add the powers together, and..." Draco stared at Harry. "Make yourself Lord of the two worlds?"
Harry gave an evil laugh, it just seemed to come naturally at that point. "You have to realise, Draco, that the whole world you know, all of magical Britain, is just one square on a much larger gameboard. The gameboard that includes places like the Moon, and the stars in the night sky, which are lights just like the Sun only unimaginably far away, and things like galaxies that are vastly huger than the Earth and Sun, things so large that only scientists can see them and you don't even know they exist. But I really am Ravenclaw, you know, not Slytherin. I don't want to rule the universe. I just think it could be more sensibly organised."
There was awe on Draco's face. "Why are you telling me this?"
"Oh... there aren't many people who know how to do true science - understanding something for the very first time, even if it confuses the hell out of you. Help would be helpful."
Draco stared at Harry with his mouth open.
"But make no mistake, Draco, true science really isn't like magic, you can't just do it and walk away unchanged like learning how to say the words of a new spell. The power comes with a cost, a cost so high that most people refuse to pay it."
Draco nodded at this as though, finally, he'd heard something he could understand. "And that cost?"
"Learning to admit you're wrong."
"Um," Draco said after the dramatic pause had stretched on for a while. "You going to explain that?"
"Trying to figure out how something works on that deep level, the first ninety-nine explanations you come up with are wrong. The hundredth is right. So you have to learn how to admit you're wrong, over and over and over again. It doesn't sound like much, but it's so hard that most people can't do science. Always questioning yourself, always taking another look at things you've always taken for granted," like having a Snitch in Quidditch, "and every time you change your mind, you change yourself. But I'm getting way ahead of myself here. Way ahead of myself. I just want you to know... I'm offering to share some of my knowledge. If you want. There's just one condition."
"Uh huh," Draco said. "You know, Father says that when someone says that to you, it is never a good sign, ever."
Harry nodded. "Now, don't mistake me and think that I'm trying to drive a wedge between you and your father. It's not about that. It's just about me wanting to deal with someone my own age, rather than having this be between me and Lucius. I think your father would be okay with that too, he knows you have to grow up sometime. But your moves in our game have to be your own. That's my condition - that I'm dealing with you, Draco, not your father."
"I've got to go," Draco said. He stood up. "I've got to go off and think about this."
"Take your time," Harry said.
The sounds of the train platform changed from blurs into murmurs as Draco wandered off.
Harry slowly exhaled the air he'd been holding in without quite realising it, and then looked at the watch on his wrist, a simple mechanical model that his father had bought him in hope it would work in magic's presence. The second-hand was still ticking, and if the minute hand was right, then it wasn't quite eleven just yet. He probably ought to get on the train soon and start looking for whatsherface, but it seemed worth taking a few minutes first to do some breathing exercises and see if his blood warmed up again.
But when Harry looked up from his watch, he saw two figures approaching, looking utterly ridiculous with their faces cloaked by winter scarves.
"Hello, Mr. Bronze," said one of the masked figures. "Can we interest you in joining the Order of Chaos?"
Aftermath:
Not too long after that, when all that day's fuss had finally subsided, Draco was bent over a desk with quill in hand. He had a private room in the Slytherin dungeons, with its own desk and its own fire - sadly not even he rated a connection to the Floo system, but at least Slytherin didn't buy into that utter nonsense about making everyone sleep in dorms. There weren't many private rooms, you had to be the very best within the House of the better sort, but that could be taken for granted with the House of Malfoy.
Dear Father, Draco wrote.
And then he stopped.
Ink slowly dripped from his quill, staining the parchment near the words.
Draco wasn't stupid. He was young, but his tutors had trained him well. Draco knew that Potter probably felt a lot more sympathy towards Dumbledore's faction than Potter was letting on... though Draco did think Potter could be tempted. But it was crystal clear that Potter was trying to tempt Draco just as Draco was trying to tempt him.
And it was also clear that Potter was brilliant, and a whole lot more than just slightly mad, and playing a vast game that Potter himself mostly didn't understand, improvised at top speed with the subtlety of a rampaging nundu. But Potter had managed to choose a tactic that Draco couldn't just walk away from. He had offered Draco a part of his own power, gambling that Draco couldn't use it without becoming more like him. His father had called this an advanced technique, and had warned Draco that it often didn't work.
Draco knew he hadn't understood everything that had happened... but Potter had offered him the chance to play and right now it was his. And if he blurted the whole thing out, it would become Father's.
In the end it was as simple as that. The lesser techniques require the unawareness of the target, or at least their uncertainty. Flattery has to be plausibly disguised as admiration. ("You should have been in Slytherin" is an old classic, highly effective on a certain type of person who isn't expecting it, and if it works you can repeat it.) But when you find someone's ultimate lever it doesn't matter if they know you know. Potter, in his mad rush, had guessed a key to Draco's soul. And if Draco knew that Potter knew it - even if it had been an obvious sort of guess - that didn't change anything.
So now, for the first time in his life, he had real secrets to keep. He was playing his own game. There was an obscure pain to it, but he knew that Father would be proud, and that made it all right.
Leaving the ink drippings in place - there was a message there, and one that his father would understand, for they had played the game of subtleties more than once - Draco wrote out the one question that really had gnawed at him about the whole affair, the part that it seemed he ought to understand, but he didn't, not at all.
Dear Father:
Suppose I told you that I met a student at Hogwarts, not already part of our circle of acquaintances, who called you a 'flawless instrument of death' and said that I was your 'one weak point'. What would you say about him?
It didn't take long after that for the family owl to bring the reply.
My beloved son:
I would say that you had been so fortunate as to meet someone who enjoys the intimate confidence of our friend and valuable ally, Severus Snape.