Over the last month, Harry had spent considerable amount of time on the Handgun Project which finally bore success in the form of a sleek and deadly handgun filled with charms. Charms that would turn it into the deadliest gun in the world.
But he was still not fully satisfied. He had charmed the handgun numerous times but most of those charms were only temporary. And even those that were permanent would only last as long as his magic did after which they'll fade in thin air, leaving behind a normal handgun which would be mostly useless against things like Trolls, Basilisk, Acromantula, Dementors, Giants, etc.
For his magic to last, he needed to carve runes into the handgun and he would admit before anyone else that he was totally ignorant about runes.
But just like with Transfiguration and Charms, the Room of Hidden things was filled with books and tomes regarding the Ancient Runes and the necessary tools that were needed to carve them on a surface. And he would have gladly used them if not for the fact that Runes is a highly dangerous subject and can lead to very large explosions if any of the runes were carved on the wrong way.
So in a sense, it was far more dangerous than even Human Transfiguration.
And yet they still teach Ancient Runes but not Human Transfiguration.
Hypocrites.
But still, the danger was real this time and he not stupid so instead of plowing through on his own like he did with other subjects, he instead chose to stop and decided to ask Bathsheda Babbling, the Ancient Runes teacher in Hogwarts.
Though on second thought, what kind of parent names their child Bathsheda Babbling.
Well, there are worse names in the world. Her parents could have named her Bobby. And wouldn't that be a name. Bobby Babbling.
Or his parent could have named him Pitter.
Pitter Potter. Pitter Potter.
He tore himself out of his musings and thought about the other task in front of himself right now. The task of creating a Trunk large enough to carry a library that would be 5 times larger than the Hogwarts library.
Upon searching, he found that the Room of Hidden things was filled with Trunks with expansion charms. But most of them were standard sized trunks and even those that were created with private commission were far smaller than what he needed so he knew that this time, he would have to create a trunk of his own.
Which meant learning the expansion charm and learning how to do it well. Plus he would have to carve even more runes on the trunk to make the changes permanent and then add a wardstone just to be extra secure. So learning runes was an inevitability at this point.
It needn't be said that he would buy and use the best quality wardsone material for his first space expansion project. It was not like he was lacking in galleons. His trust vault and his bank robbery and other thefts had already seen to his needs and right now he was probably the wealthiest child in Magical Britain.
But even if all his wealth somehow vanish into thin air, he was not worried because he could always ask Besalla to give him some of her Basilisk Venom and sell it at a high rate in the Knockturn alley. She was usually in a good mood when she finished feeding on a cow and would not mind parting with some of her venom if he asked her nicely.
Or he just go and rob a bank once again.
But until then, he would take all the books related to charms from the room of Hidden things and keep it in the original trunk that held a library room of it's own. He had to admit that the more he learnt about charms, the more he liked the subject.
Transfiguration was his second favorite subject at the moment and Defense in dark arts being the third favorite one.
Of course, all this could easily change in the future if he found something else that caught his fancy. But for now, he knew that he was head over heels for Charms.
While he was reading one of the books on Expansion charms, he also found that Newt Scamander, the bloke who wrote the book called 'Fantastic Beasts and where to find them' had built such a large space inside his suitcase that he could easily keep thousands of species of endangered animals, birds and plants inside it.
So in hindsight, his dream of creating a library that was five times larger than the Hogwarts' library was really not that big of an ambition.
Well, all those things would come later. He realized that reading continuously for the past few hours with the help of the Diadem had tired him out by quite a bit and he was in no position to study anymore.
Plus, he was feeling lonely and he needed some fresh air, so after one last look at the Marauders' map to make sure that there was no one in the near vicinity of the door, he left the Room of Requirement and watched it's door fade in the wall.
The Room of Requirement was a treasure on it's own. A treasure that he was not willing to share with anyone else. Well maybe he would share it with Hermione sometime in the future. She was kinda like a friend so he was willing to do this much for her. And she gave him hugs so there was that.
With those thoughts, he left the corridor in search for his hug machine.