Harry nodded. He'd watched two-thirds of the class do this. Harry touched the tip of his wand to the medallion and gently fed his raw magic into it. The medallion was a thirsty one, he could feel it pulling on him.
After Harry was done, Professor Babbling cast a spell then picked the medallion up. Her face lit up in a smile. "Very good. It held the magic you poured in."
"Did you think it wouldn't?" Harry asked.
"This many runes in an unknown set... I had no idea if it would be stable, but it seems to be."
"What would have happened if it hadn't been stable?" Hermione asked from the other side of the front row.
"Well, if it was unstable, when Mr. Potter pushed magic into it, the thin metal would have snapped. This wasn't very dangerous to test, which is why I was willing to do it."
Harry accepted the medallion from her. He could feel his magic contained inside it. It was a wild feeling.
"Report back next class if you can determine if it has an effect. This is something I've never seen tried and I apprenticed with the rune carvers of Murano, near Venice. They've seen everything, been commissioned to do everything."
"Yes, Professor."
She cast a Tempus spell. "Oh. We won't have enough time for another project. We'll finish up next class and begin to revise for the final examination the class after that. Well done, students. Well done on these projects. I've had a lot of fun reviewing them – and hopefully you can see what you might get up to in next year's class. There are more languages to study, but the applications get more interesting, too. Think about it."
Harry returned to his head. He put his medallion in the pocket of his robe. He needed to find a string or a chain. Silly. He should have bought one when he got the medallion itself.
The class began to empty.
"Mr. Potter?" the Professor called out.
Harry kept his face neutral. How did he keep getting held back?
"Yes, Professor."
She beckoned him back down to the well. Harry put on his most neutral expression and complied. "I am curious about the runes you used, specifically that you didn't limit it to only ghosts. But spirits more broadly."
"Why?" Harry asked. Was this a strange thing?
"Just humor me. Tell me where the idea came from."
"Well, a rune against ghosts would be useful. But I have a ghost I'm avoiding as well as Peeves."
"Peeves? The poltergeist?"
"Yes." And he said no more about that. Pimp-Master Potter? No, no, that story wasn't getting out.
"So you actually intended to handle more than one type of spirit? That was what kept you working on this for so long?"
"I suppose so."
"You started the hard work earlier than almost anyone, Ms. Granger excepted. And you were still working until last week."
"Until three days ago," Harry corrected.
"I see. And most of that was on this definition of spirit?"
"Almost all of it. The other words of the phrase are all common enough."
"Yes, I suppose they are. Your definition of spirit is clever, Mr. Potter. The whole thing is good work. Though I did want to caution you."
"You don't think it will work?" Harry asked, unhappy.
"No, I'm almost sure it will."
So what caution did she intend to give?
"It may work too well, perhaps. I think you might have yourself a variation on what the Wardens of Azkaban use at the prison to corral and control Dementors..."
Really!
"Of course, the Dementors are back at Azkaban so we can't test that."
Harry didn't miss the opportunity.
"Since this is a unique definition, I've been considering it. It's broad, very broad, and I expect the effects won't be limited to just ghosts and poltergeists. Hags have a bit of a spirit essence to them. Dementors. Maybe ghouls, too."
Well, what did that mean? "Right," he said, fully confused.
"Just keep this little secret to yourself? I doubt anyone in the class would think this related to Dementors, or other spirits, but I thought you should have my full opinion."
"Yes, Professor."
"Well done. It was a hard topic you set for yourself, but a clever solution. You've done well, Mr. Potter."
"Thank you."
As Harry left, he began to think about Dementors again. If this rune set repelled them, could he make something that trapped them or killed them? The Sunfire was a rather slow method, as it took at least three weeks.
He wondered.
It went onto that list of things that were 'interesting, but not immediately important,' like much else he learned at Hogwarts.