Disclaimer: JKR owns Harry Potter's arse and John Constantine has Vertigo (or is it the other way round?).
Sorry about the extended delay folks. Hopefully I'll be able to update more often now.
RaIsInG hElL aT hOgWaRtS
A Hellblazer/Harry Potter Crossover
Chapter 7:
CLASS
It was time for the 6th year's first Defense Against the Dark Arts lesson with Professor Constantine. Many students were showing more than the usual reluctance to attend. John's reputation had definitely had an effect.
Harry and Hermione dragged Ron into the classroom.
"Come on you big baby!" Hermione sighed. "He can't be as bad as all that."
"No," Ron wailed, "he isn't. He's even worse!"
"Can't blame a lad for telling the truth."
The unexpected voice came from so close behind them that all three nearly jumped out of their skins. Constantine laughed as the whole class stared at him in shock. He definitely wasn't there a moment ago, and he hadn't apparated.
John caught his breath. "Right, bums on seats everyone. And close your mouths, you're catching flies. Put your textbooks and wands away and start taking notes. What you're going to learn today is how to deal with ghosts and other free-roaming spirits. You've already had plenty of experience with the ghosts here but, they're all relatively friendly. There are poltergeists, wraiths, specters, entities and other types of ghosts that can be downright stroppy. Possibly even homicidal. There are also ghosts that are imprisoned because of how they died. These kinds aren't violent or nasty on purpose, but they can still affect you subconsciously. In these cases you have to confront the ghost and then either exorcise them or release them."
During all this, Constantine had been walking around the room and snatching notes, make-up applicators, and other paraphernalia from students, without ever once interrupting his own lecture. When he reached Neville's seat, Trevor, Neville's toad, leapt from Neville's pocket. John caught him and fielded him perfectly back into Neville's pocket.
John continued. "These kinds of spirits are never co-operative, which kinda makes confronting them a bit of a poser. What you need to do is summon them."
He then produced a knife from his pocket and strode over to a bare wall. He then turned to face the class. "Now bloody well pay attention, I won't demonstrate this again. It hurts like hell and the ghosts around here won't like it." John then slashed open the palm of his hand and called out, "Y nommine Asmodeus spiritus avanti!" As he said the last word, John slapped his open, bleeding palm against the wall.
Nothing happened.
John walked quickly over to his desk, sat down, smiling, and began to bandage his hand.
When he'd finished, he looked up at his students. They were all staring at him. Constantine pointed at the bloody handprint on the wall.
The wall then seemed to explode as every ghost that haunted Hogwarts came hurtling through, including Peeves the poltergeist, who was screaming obscenities. Within moments, the entire classroom was packed with ghosts.
Nearly Headless Nick, the Griffindor ghost squeezed his way over to Constantine's desk. "What is the meaning of this, sir?!" he bellowed.
John grinned at the ghost. "Oh, just a practical demonstration for the sprogs. All done now." He then stood up. "You can all bugger off now. Cheers."
The ghosts trudged sullenly out of the classroom. All except for Peeves. John shot him a dirty look.
"Peeves, you even think of throwing that water balloon at me," he said in a pleasant voice, "and I'll personally make sure that a certain rhyming demon comes looking for you."
Peeves stopped in mid-throw. "Not Etrigan?"
John flicked his knife at the balloon.
"Now, bugger off!"
Peeves flew from the room, dripping and cursing all the way.