In Harry Potter as Neville Longbottom

The next day during breakfast, Neville got a letter from his Nan telling him that Longbottom or for that matter any of the 28 sacred noble families in Europe have stopped using Grimoires decades ago. Longbottom family grimoire, if there ever was, must have been burnt or destroyed during goblin wars.

"Huh!" sighing Neville burnt the letter and then went for his classes. During the potions class, when he got free time, he was going towards the library when it clicked him. The biggest source of such information was not the books but the ghosts in the castle.

These ghosts were here from the time Hogwarts was built and hence they must have known about these grimoires. And there was a special ghost in the castle, the daughter of Rowena Ravenclaw, the Grey Lady. But now, how to find her?

"Well, it seems I need to go on a night tour to visit a particular office!" I said to myself and then decided to visit the lake outside and spend the rest of the day around it.

At night, while my roommates Harry Potter and Ron got up and left for their regular night tour, I also left the dorm stealthily. My goal was the office of Flitch's office and a certain map that was kept there.

After waiting for a while when I saw Flitch going with his cat on the second floor and I dashed towards his office. Without making too much noise, I carefully searched around the cabinets he had in his office.

There was a lot of stuff kept here. Some are too old to even properly recognise.

"Found it! Nice." I finally found the marauder's map and went back to my dorm with it. With this, I can avoid a lot of trouble in future.

Three days later, during weekends, I opened the parchment.

"I solemnly swear that I am up to no good," I said while pointing my wand to the map and then the ink flashed like a spider's web and the whole of Hogwarts came alive on my fingertips. Surprisingly, Ms Helena Ravenclaw was in professor McGonagall classroom.

"Well, it seems she really is Ravenclaw. Time to find her." Nev said to himself and started going towards Professor McGonagall classroom. He found Ms Grey sitting and reading through some notes on Transfiguration.

<><><><> Nev POV<><><><>

"Ahem, Ms Gray? May I have a few minutes of your time?" I asked cordially.

"Yes? You are not in Ravenclaw if I am not wrong. Well, what are you looking me for?" She asked me in a not so friendly way.

"Ms Grey, I was looking for any information about Grimoires. And I think you might be able to help me. Please."

"And why is that?" Ms Grey asked in a loud voice that confirmed that me looking into her past was not welcomed.

"Ahem...Please don't get angry. How about we talk somewhere else? I think If you give me some time, you will find the conversation worthwhile." I offered to her and then she looked at me and started floating outside the classroom and then she went towards the astronomy tower.

"Damn it! I hate that tower. There are so many other places in the castle anyway!" I sighed again and started chasing after her.

Fifteen minutes later, I reached on top of the tower. It was basically empty in the morning.

"Now? Tell me, young wizard, what do you have to say?" Ms Grey demanded.

"Well, Ms Grey I know your history. It was not clear at first but I somehow stumbled across the truth. In exchange for the knowledge about the Grimoires, I can tell you the present location of your mother's lost diadem. How about that?" I proposed a deal I knew she can't refuse.

"You know where my mother's diadem is?!" she floated towards me. Looking deeply into my eyes she spoke, "I can tell you everything about Grimoires only after I can confirm the location of the diadem."

"Cool. Fine by me. It is hidden inside the Room of Requirement or as the house-elves say Come and Go Room. The Room is located on the seventh floor, opposite a tapestry showing Barnabas the Barmy trying to teach trolls to dance the ballet.

To make the Room appear, a person has to walk past the section of blank wall three times concentrating hard on what is needed. The diadem is basically sitting there and you can check it if you want. I can wait." I told her openly and plainly.

I know she won't trust me if I play tricks with her and besides, she won't trust anyone easily after Voldy the Baldy but I might have a chance.

"Ghosts can't enter that room alone, you know that? Right?" She said angrily. Maybe she thinks I am joking or playing a prank on her. Shit.

"No No...I didn't know that. Wait, I can bring you there. Come with me." I offered and took her with me to the seventh floor. After finding it relatively empty and sure when no one is around, I walked three times past the blank section of the wall thinking 'I need a place to hide something', 'I need a place to hide something very important and voila...a door appeared.

"Thankfully, the book was clear about this," I said to myself and then looking at Ms Grey, I called her "Please come!"

Ms Grey followed me rather sceptically but she did enter the room in the end. The room was full of broken things and thousands and thousands of books. It also had things like chipped bottles of congealed potions, hats, jewels and cloaks apart from other items. Yes, most of them were old and torn but I was surprised why no one ever took these jewels anyway?

"There, I think that is what we are looking for Ms Grey!" Finally noticing a discoloured old tiara lying near a statue I pointed to Ms Grey who was just floating behind me.

It was just placed there without any strong magical barrier or charms on it. Though I knew it was a Horcrux and deadly if not handled properly.

"This, This is it. It was always here." Ms Grey got too emotional on looking at it and tried to hold it which made me jump in front of her.

"Stop. That's a deadly thing now. It is enchanted with powerful black magic and I am not sure what will happen if you touch it. It might end up killing you or me or both." I shouted and prevented her from touching it.

"What! Who did it?..... It must be him...He betrayed my trust and he did such a vile thing...It's all my fault...It's all my fault....I failed my mother....." Ms Grey went from being angry to sad and I think it was my first time watching a crying ghost. She was crying pretty bad and even I felt a little bad for her.

I mean if this was the last piece of my connection between my parents and someone abused it like this, I would have slaughtered his entire family.

For the next half hour, I stayed, silent, standing behind her. I let her cry her tears and collect herself. Only when she stopped crying did I speak,

"I have no means to remove the black magic on it right now.

I know what it is but If I tell you, you owe me for this. I can also promise to remove the curse on it in future and return it to you or whoever you want but that will make it two favours. I know you can tell this to Dumbledore and others but I think you should trust me.

I don't want this diadem or anything special. I just hope you can share your knowledge with me. In return for those favours, I ask you to teach me whatever you know and I promise to fix this diadem in the next three years.

Ms Grey looked at me and said "You know I was one of the first Ghosts here. I know a lot of secrets, hidden rooms and other things. Do you just want my knowledge? Are you sure?"

"Yes, Mam!" I finally smiled.