SEVERUS' POV
He couldn't believe it.
The boy he thought was like a younger version of himself turner to be the most incredible person he had the pleasure to meet.
Sure, he wasn't as powerful as the two leaders in the war, but power is something that grows with time, not to mention that according to what he seems to feel now that the Fidelius charm isn't messing with his senses, the boy is at the peak of the second stage of magic.
That wasn't what Severus meant by considering Harry as a the incredible wizard he is.
He can do wandless magic! Not the half-baked focused accidental magic that some people can do, like create bursts of fire or push people away, but controlled magic like transfigurations.
It would have been enough if it was only that, Severus already considered it as amazing achievement.
But no, the boy also created a way make magical people to power up all his inventions willingly, by using a game he made with his friends.
As a half-blood potion master, Severus knows that the biggest thing that limits magical progress in terms of potions is the magical people's inability to make potions without constant attention on them, making it so every big potion's supplier need to make them by hand and have someone who knows potions well enough to follow his instructions.
With all the needed healing potions, antidotes and other hospital related potions, which people are only willing to buy from potion's masters, the time each of them have to do research about new potions lessens more and more as new potions are discovered.
Even self-stirring cauldrons are only helpful for low-level potions, as stronger ones need to be imbued with specific intent to work.
Harry's way of storing magic from people was tried before, but no one ever managed to find a way to store it nor could anyone find enough willing people to store magic from.
Even if nothing else seemed enticing, just the possibility to create a factory that makes potions without much needed help was enough to make Severus join him, after negotiating the terms, he is Slytherin when all said and done.
"I have a few conditions before agreeing." Severus said and at the nod of the other side he continued.
"First of all, I won't be sacrificed, nor would I work for you- if we do it, we are partners." This was the most basic thing Severus needed, which was why he was surprised when Harry shook his head.
"No, we won't be partners, we will be business associates."
"What's the difference?"
"Partners are equals in everything, splitting 50/50 everything they get and the responsibilities are equal, associates aren't, if you do more work you get more benefits, for example, if we create a potions factory where only my inventions work, you will get money for your connections and getting supplies, the rest will go to me."
"What about the war?"
"I will tell you everything that might affect you negatively and you will do the same, plans that involve you will be fully revealed but those that don't won't."
Severus didn't like that, it meant he will be vulnerable for surprises, the best time out of working for both sides was the knowledge it brought him.
"No! You need me! You need someone on the inside of both groups. So either partners or nothing!"
Half-way through his ultimatum the boy smirked.
"No I don't, I have spies on both sides already, and I can take it slower and become an 'official' potion master after finishing school." The way he said official made Severus remember he was talking to a boy who created miracles already, and helped him create the liquid luck potion on his third year, something that might seemed reasonable at the time, but now that the charm stopped affecting him made him see how absurd it was.
"Fine" he said sighing. "We will do it your way, but I want 35% profit from every potions related enterprise, the ability to vote on any other members of our group, and I will say no to any life threatening requests."
"I will give you 20% profit, the ability to vote on ADDING more members, saying no within reason, and access to my library."
"What is so special about your library?"
"Oh, just look here."
Harry said and took out of his pocket a palm-mirror.
Pouring magic into it, a face appeared on it like one of those opinion mirrors women love.
"What subject are you searching for?" The mirror talked emotionlessly.
"Potions." Severus said raising an eyebrow toward the boy when names of books, some he read, some he only heard about, and some not even that appeared alphabetically.
"Would you like to narrow the search?"
Severus now was truly intrigued, but is it only a library, or more?
"Give me everything you have on the archina potion!"
The mirror changed, now instead of showing books it showed chapters from different books, some that just by seeing them Severus wanted to start reading as they were things he searched for a while now.
But now wasn't the time, now he needed to give Harry an answer, and with incentive like that there is only one answer to give.
"Where do we start?"