FINITE INCANTATUM.
Mr Weasley and Mr Malfoy, that is enough.
There will be no discussion as to who started this shameless display of childish behaviour. The fact of the matter is that you are both flinging dangerous hexes around in a public area, and - to be blunt - making asses of yourselves in the process. You will cease and desist this reckeless disregard for saftey and common sense.
Thirty points each, from both your houses, and a week of detentions for the both of you. You will serve them together, under my supervision, starting tonight. If I hear of another incident such as this, that sentence will be doubled. Do I make myself clear?
Harry, if you would please finish up your journal entry quickly, and get Mr Longbottom out of the closet? I'm afraid he's in the one with the Boggart, and the last thing we need right now is Professor Snape in a housedress roaming the castle.
And don't forget about that essay I asked you for, Mr Malfoy. Three feet of parchment, by Friday. Mr Weasley, I want one from you as well, on the typical household usages of Class X and XX Magical Creatures. Same length, same deadline. Understand?
Now, I suggest you make yourselves scarce, for when Professors Snape and McGonagall hear of the house points you've lost today, I expect they will be none too pleased. And, in your case, Mr Weasley, I would avoid Miss Granger for the same reason as well, lest you wind up with a pair of tomatoes elsewhere other than on either side of your head.
As for the rest of
you, don't you have somewhere else to be?