It took most of January to get a potion brew going that was of acceptable potency to what would be required. That had required a sacrifice of shelflife, down to something less than a month, which simply wouldn't do. Still, it was proof of concept that her idea for using a still to make potions worked. Probably ONLY in a place with high magic, like Hogwarts, but it wouldn't be too hard to produce a few good batches here, and then perhaps buy a place on Diagon Alley, which should have, if not as potent a concentration of magic in the air, then at least enough for her purposes.
Beyond that, she had worked out her spells. Sadly, she had hoped that some might provide her with a force multiplier for her plans for later, but while she knew spells to heat something, charms to freeze things, and even generate electricity, fire, stones, and ice on command, she was disheartened to note how not one 'protected' what she made from other casters, which meant none would be useful to her purposes.
She spent most of the rest of that month working on her potions and going over her maths with her spells. Her hope was, obviously, that combat, especially ones involving her, could be avoided, but she was no fool. She had had to fight for her life on Halloween, and that had been a plot not even directed at her, as at that point she'd been mostly an annoyance to first years, nothing someone who could command a troll would care about.
She'd also realized how lucky she'd been. A magic user would have blocked her spell. Shields existed after all, and were ubiquitous in what magic they shielded again. Spellcraft couldn't get through them…but air could? She began to research that topic next, going over some of the background of Shield Spells in general, moving some of her books around in her reading schedule to gain their knowledge now rather than later.
All the while life continued. January gave way to February at some point, and she continued to excel in the one class she had, and then vanish at all other points. She even discovered that 'secret passages' in Hogwarts weren't set things, much as they seemed to be. You could command them into existence, and close them just as easily with the Rites she knew, so she worked out a small trap door slide from her room to the bathroom, to allow her to come and go with no one the wiser.
She was still confused how it could be a slide going both ways, of course, given she was much lower down than the tower she slept in the bathroom was, but it was magic, and it probably had to do with how the castle's interior wasn't really where or when it seemed to be, so she decided to just accept that, for the moment. No, her personal projects took precedence over a bit of idle curiosity.
Mid-February is when she finally exhausted her supply of potion making ingredients, which forced her to make a choice. Her batches had improved, to the point of being very much viable products for sale. However, doing so was risky in the extreme, as it would reveal in part some of her goings on in the school, and she was working hard to keep that to herself, so she could either focus in other areas for the remainders of the year, or find a way to sell them anonymously, so she could afford more supplies.
It took most of a week for her to decide, and she went with the more ambitious approach. Going to Madam Pomfrey, she presented the nurse with one of her potions, and had her compare it to the stock she was using, made, as Hermione was shocked to find out, not by Snape. She had expected him, being a Potion Master, to insist that all the potions in the school were of his make, but it seemed he had actually said much the opposite, claiming he had no time to help with it.
She quickly judged Hermione's brew to be, if not superior to what she received regularly, then at least comparable to it, and given she always had need of the stuff, she made a deal with the young girl. A few students always had more potion kits than they needed, and they'd often wind up in the Castle's inventory. If Hermione could supply her with a regular batch or two of her brew, the Nurse would…misplace a few of those kits, even from later years, for her.
Hermione was quite pleased to find out that her work was as good, if not better, than that of others who did this sort of work for a living, and quickly agreed. After all, a 'batch' to a wizard was six vials of the potion. That was because, as most potion masters would tell you, the good stuff in potions came to the top, while the dredges near the bottom were of little use, and should be disposed of. Even a few centimeters down from the surface of the potion saw the potency drop by almost an order of magnitude, and it kept dropping as you got lower down in the cauldron.
Her method, thanks to how the still worked, was giving her a bit more. The mixing, using water pressure to keep a large paddle spinning at various rates, that she could modify if she was in the room with it, was larger than a spoon or the more common instruments. It helped to keep the ingredients from settling in the bottom, and gave her about five times what would normally be viable from a potion mixture.
So, with access to even more varied ingredients, she set to work, while refining her other ideas for magic. Her spell list, sorted now by utility, was growing swiftly to be an interesting project, especially as she began to see the flaws in the shield spells. They protected the caster, but not the space around them. Better, they didn't produce air, instead acting as a filter for what was coming in from outside.
It gave her methods of attack she would not have considered, especially since, as she noted, most shields were…negligent in their defense of kinetic impacts. Oh, they had SOME use against them, but it didn't take long for her maths to begin to show just how bad they'd be at providing protection against even the most basic weapons she was familiar with from the muggle world.
A handgun wouldn't be able to pierce the shield of a moderately skilled wizard, as it was a single point of impact, and the spell automatically reinforced such. But a shotgun, or something that fired rapidly? That would actually be worse for the spell than most attacks a magical could launch, given the automatic redistribution would constantly shift around, meaning it would eventually be too thin at an impact site to provide more protection than a sheet of parchment.
Worse, shields, at least the ones she knew, were contiguous things. They were a solid mass of magic, not simply counters, and as such, breaking them in one space, shattered the whole of them. At least muggle body armor didn't have that weakness. Even if you did get through it via some method or strange attack, the whole of the armor would not simply come undone and leave you open to more damage. They also didn't leave you exhausted when they failed, which a magical shield would.
Of course, that was only so useful. A shielded magical was still as dangerous as a tank, and if you didn't attack fast enough there were ways to control the bullets in the air as easily as a gout of flame. One shot was likely all you'd get off on them if you were alone. So while guns were a good tool to use if you had the training, planning, and numbers to make use of them. That meant they weren't good enough for her purposes, given, while she expected to have all three eventually, they were only about the same use as spells.
Her studies would be interrupted only a few times in the month, as those who had taken up their challenges, and allowed them to be seen publicly, were of interest to her. Especially as some were from the later years, and would provide her with an idea of what the teachers saw as truly difficult spellcraft. So on a day in late February Hermione went down to the Great Hall to watch three such tests.
They were for a Gryffinor, a Ravenclaw, and a Hufflepuff today, which was an interesting mixture. Most Slythren tended to make their attempts in private…and as she'd thought, most failed. Even those trying only for potions, showing that, while Snape might cheat for his beloved Snakes, he wasn't about to let their skills go untested, a fact that seemed to surprise those of them who tried it.
For today, they started with the Ravenclaw, a fifth year at that. They had limited themselves to three subjects, namely Potions, Herbology, and Divination. Some questioned why you'd be taking the Rite for an elective course like Divination, but she knew it was because passing the Rite simply meant you were already proficient in the skill the course taught, and you could join the next year when that came around, or if it was Seventh Year, you could claim a moderate level of mastery in the subject.
Sadly, she didn't get to see what Divination would look like for the Rite, as while they passed Snape's test, with some difficulty as the man was vicious in his standards, it was the Herbology challenge that they failed. The plant, a kind of honeysuckle, needed to be very delicately prodded into producing the pollen from inside itself, and the Ravenclaw was just that tiniest bit too rough with it, causing the thing to wither and die.
Still, she seemed pleased with herself as she got up. Wiping her hands off, she nodded at the teachers, and admitted her failure, thanking them for their time and effort, Snape scoffing at her, but the others looking apologetic. Even Professor Sprout, who seemed willing to give her another shot, but Headmaster Dumbledore reminded her that wasn't allowed, and that the test, while difficult, was fair.
The next up, a seventh year boy, was only taking Herbology, his Head of House quickly bringing up his test, a plant that looked for all the world like a dozen or more had been put into some kind of blender and fused together. It was a hybrid, as Professor Sprout explained, but chose to say nothing more about it as she stepped back, obviously expecting the student to take the initiative from there.
The student, sweeping his long hair out of the way, approached the plant, and quickly placed his wand at three points, bottom, somewhere in the middle, and the top, before stepping back, and taking a moment to study the problem. He then poked his wand at the thing in various places, taking a moment each time to inspect something, with both his magic and his eyes, before finally walking away and standing in front of Professor Sprout.
The young man began to list off not only the seventy-five plants that made up the hybrid, but also why Professor Sprout had used the ones she had, detailing each ones' use in various magical crafts, from Runes to Potions, and even some that would simply allow the plant to have a pleasant smell. He then proceeded to list the spells used to create it, as well as how long it would live, and the primary point of viability for it.
Professor Sprout beamed at the young man, saying that he passed, and with his skill, he might one day take her seat at the table here in Hogwarts if he wanted. Hermione, who had taken in quite a lot of knowledge on Herbology, found herself impressed. It was humbling to know that she didn't even recognize the spell he had used to study the thing, and she could only identify eight of the plants used by sight, and had had no idea WHY someone would make such a thing.
The final student of the day, a Third Year of her own house she didn't recognize took his place before the teachers, and Professor McGonagal came down, muttering to herself something Hermione couldn't quite catch. The older witch then set about casting her spells, pulling bits of the floor up in various forms, and with twitches of her wand, slamming them together in a variety of ways.
Finally, when she was done, she looked at her construct, nodded, and ordered the boy to change the whole of her monstrous looking art piece into a liquid form and then hold it in that shape for five minutes, without allowing any single element to backslide. The student swallowed, hard, and Hermione herself was looking at the thing with rapt attention. She knew enough about Transfiguration to know this was far and away beyond the skills of a Third Year, and just on the edge of what a competent Fourth Year would be capable of.
The boy didn't get to try, however, as Headmaster Dumbledore, with a heavy sigh, waved his wand, and with a flourish, caused the ugly thing to assume a more…stable shape, reminding Professor McGonagal to keep her tests to what he had approved previously. She looked about to protest, but then turned sharply around, and the student, seeing this was now a far easier task with a simple rectangular prism to deal with rather than the shape it had been, got to work.
To be fair, he still wound up failing, though Hermione had to wonder if some of the reason for it might have been being challenged with something impossible for him to achieve. Still, he HAD failed, and even with that taken away, he might have done so anyway, so she decided to drop the thought, as she got up, looking towards the Seventh Year Hufflepuff talking with his Head of House animatedly, obviously excited about her offer.
She made a mental note to ask Madam Pince for her recommendations on books on Herbology next, though that was one of dozens of subjects she had to talk to the woman about. She would first, as her potions became stable and her spellcraft was taking shape, ask after tomes and whatever else the library had on wand lore. After all, while her own Vine with Dragon Heartstring had served her well, one made by her own hands would probably serve her even better.