Kazimeriz's lips widened, revealing his white teeth and liver-coloured, elderly gums... making him look more than a little skeletal. But he couldn't help grinning at the boy. "I see."

He paused, surveying the boy. "Ten points from your house for using a spell against another student in my class without my consent or approval. However... To your house... I award fifteen. For creative application of the assigned charm and illustrating an excellent point for your classmates: even a defensive maneuver can have an offensive application. Conversely, offensive manuevers may be used defensively as well. Be seated, Kettleburn. And no other student is to cast against a classmate without my express permission to do so."

Newtington re-entered the class. "Excellent. Much better. Now wipe your face and be seated. And pay attention." He nodded to the boy, then turned to the board and wrote:

HEXES

"Who can name one commonly used hex and explain its effect?" he looked around the room, waiting for answers.