"Right, settle down you buggers," the man yelled as he walked into the busy classroom. "My name is John Constantine and because someone cheats at cards," he groaned and frowned in the general direction of the principal's office, "I'm here to teach you how to defend against dark magic today."

The class exchanged slightly confused looks; the man wore a beige trenchcoat, a loose tie, dirtied trousers... he looked less like a teacher and more like a used car salesman at a bar.

"Sir," one of the boys near the front carefully said, "are- are you our teacher? I thought that teachers all wear black robes."

Constantine glared at the kid briefly, but then his face shifted into a smirk.

"Right you are, lad. Seem to have forgotten mine at the stables. Do us a favour, and, go fetch it for us, ey?" he said.

"But- sir, that's the other side of the school," the boy protested. "It's a 20-minute run!"

"Then you best get going, right?" Constantine chuckled. The kid sighed and defeatedly left the classroom.

"Roight!" Constantine yelled and clasped his hands. "What's the last thing you lot learned here?"

"Page 54, sir," a young woman near him said and offered him her textbook. He took it and started turning its pages.

"Ineffective... outdated... last one I saw someone try this one they lost two fingers!" he said and grinned at the class. They did not share his exuberance. He threw the book back to the girl.

"Bleedin' hell. No wonder this school loses a student almost every year," he murmured to himself. "'Aight, listen up you lot. I ain't gonna teach you how to defend against dark magic. I'm gonna teach you how to royally fuck up whoever's trying to hex you, sound good?"

The class responded in a mixed manner - some students lit up excitedly, some grew worried. Constantine reached into his breast pocket and pulled out a crumpled pack of cigarettes, lighting one and taking a long puff.

"Good," Constantine said contently. "Perhaps a demonstration is in order - I heard it's a 'good teaching technique'. How many of you have summoned a demon before?"