Spite
"In the year 1000, Muggle distrust of the Magical community reached new heights," croaked Professor Binns slowly. His voice was that perfectly irritating tone where it was too quiet to fully hear, and too loud to fall asleep with. "A Muggle paranoia-epidemic broke out as well, resulting in a span of wars and a lot of burned literature. Meanwhile, the Magical community first opened Hogwarts, which I assume you all know about."
Binns scanned the classroom with gray eyes, wondering if anyone even picked up on his lame joke attempt. As he expected, nobody in the assembly of fourth years seemed to notice he was there. This treatment never really bothered Binns, but somehow…today…it was a little irritating. After all, it was his three hundred eighty-seventh Death Day, and not one of his students even remembered.
"As you well know, the four houses are named after the four Founders. And naturally, you know the tale of the Chamber of Secrets…not so much a secret anymore, is it?"
No response. Not even a chuckle at his second in-vain joke attempt.
Sighing, Binns continued his lesson. He even added a bit of inflection to his voice, hoping to get some of his students to pay a minute of attention. "After he constructed the Chamber—now known to be a fact, not a myth—Slytherin left the school."
Binns paused, hoping if someone would look up now. This time, a boy in the third row lifted his head up off his arms, clearly wondering why his teacher's raspy voice had suddenly stopped.
Heartened by the boy's reaction, Binns went on. "That's right, he left the school. Never to return again." Keeping one eye on the boy, Binns was stunned to see him sit all the way up, his face oddly alert. "He never spoke to Gryffindor, Ravenclaw or Hufflepuff again."
The ghostly teacher was shocked. It was oddly refreshing to get this reaction from a child. Though droning was so much easier, apparently a little inflection could go a long way. He continued speaking, watching the boy exclusively. The child was looking Binns right in the face, his chin on his hands.
"From that day, Slytherin was know for his deviousness and secrecy and—"
Splat!
Something flew through Binns' face, smacking the blackboard behind him. A second splat ensued, something wet going through his shoulder. Slowly, Binns turned around. Two spitballs were stuck to the blackboard. While his back was turned, a bombardment of five more whizzed in, going through his back and neck.
In his painfully slow manner, Binns wheeled around to see the entire class holding in laughter, as they looked to the culprit in the third row. That boy, Binns' first listener, was licking bits of paper and blatantly flinging them at his teacher with his wand.
If there had been blood in his veins, Binns surely would have paled. Instead, he wheezed, "Essay. Pop test."
The class groaned collectively as Binns' secret weapon appeared on their desks. "Thank your friend after class," he added coldly.
Riffling transparent note cards between equally pale fingers, Professor Binns cast a wary eye over his students. The little punks were more alert than they'd ever been in his class, due to the fact that he'd assigned an hour-long test for the remainingforty-minute class. Their little hands flew across their parchments furiously as they fought a losing battle with the clock.
This is what he got. Years and years of devotion to the Institution, and all he got was a blackboard littered with spitballs? This is what he got for inflection and a little bit of effort. If that was how these little rats would treat him, then they deserved a boring teacher, and they deserved tests they'd doubtlessly fail.
Binns clenched a fist, eying that boy in the third row. If you can't beat them, arrange to have them beaten… he thought to himself. Spite would be his tactic this time. Spite and unfairness. It did'n matter how good that essay was.